creation_sourcecode: {{
    "language": "Solidity",
    "sources": {
      "@openzeppelin/contracts/access/Ownable.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../utils/Context.sol\";\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor() {\n        _transferOwnership(_msgSender());\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        _checkOwner();\n        _;\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view virtual returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if the sender is not the owner.\n     */\n    function _checkOwner() internal view virtual {\n        require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby disabling any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        _transferOwnership(address(0));\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        _transferOwnership(newOwner);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Internal function without access restriction.\n     */\n    function _transferOwnership(address newOwner) internal virtual {\n        address oldOwner = _owner;\n        _owner = newOwner;\n        emit OwnershipTransferred(oldOwner, newOwner);\n    }\n}\n"
      },
      "@openzeppelin/contracts/interfaces/IERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (interfaces/IERC20.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../token/ERC20/IERC20.sol\";\n"
      },
      "@openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.4) (token/ERC20/extensions/IERC20Permit.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't\n * need to send a transaction, and thus is not required to hold Ether at all.\n *\n * ==== Security Considerations\n *\n * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature\n * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be\n * considered as an intention to spend the allowance in any specific way. The second is that because permits have\n * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should\n * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be\n * generally recommended is:\n *\n * ```solidity\n * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {\n *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}\n *     doThing(..., value);\n * }\n *\n * function doThing(..., uint256 value) public {\n *     token.safeTransferFrom(msg.sender, address(this), value);\n *     ...\n * }\n * ```\n *\n * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of\n * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also\n * {SafeERC20-safeTransferFrom}).\n *\n * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so\n * contracts should have entry points that don't rely on permit.\n */\ninterface IERC20Permit {\n    /**\n     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,\n     * given ``owner``'s signed approval.\n     *\n     * IMPORTANT: The same issues {IERC20-approve} has related to transaction\n     * ordering also apply here.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `deadline` must be a timestamp in the future.\n     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`\n     * over the EIP712-formatted function arguments.\n     * - the signature must use ``owner``'s current nonce (see {nonces}).\n     *\n     * For more information on the signature format, see the\n     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP\n     * section].\n     *\n     * CAUTION: See Security Considerations above.\n     */\n    function permit(\n        address owner,\n        address spender,\n        uint256 value,\n        uint256 deadline,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    ) external;\n\n    /**\n     * @dev Returns the current nonce for `owner`. This value must be\n     * included whenever a signature is generated for {permit}.\n     *\n     * Every successful call to {permit} increases ``owner``'s nonce by one. This\n     * prevents a signature from being used multiple times.\n     */\n    function nonces(address owner) external view returns (uint256);\n\n    /**\n     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.\n     */\n    // solhint-disable-next-line func-name-mixedcase\n    function DOMAIN_SEPARATOR() external view returns (bytes32);\n}\n"
      },
      "@openzeppelin/contracts/token/ERC20/IERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n    /**\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\n     * another (`to`).\n     *\n     * Note that `value` may be zero.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 value);\n\n    /**\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n     * a call to {approve}. `value` is the new allowance.\n     */\n    event Approval(address indexed owner, address indexed spender, uint256 value);\n\n    /**\n     * @dev Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @dev Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @dev Moves `amount` tokens from the caller's account to `to`.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transfer(address to, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Returns the remaining number of tokens that `spender` will be\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\n     * zero by default.\n     *\n     * This value changes when {approve} or {transferFrom} are called.\n     */\n    function allowance(address owner, address spender) external view returns (uint256);\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\n     * that someone may use both the old and the new allowance by unfortunate\n     * transaction ordering. One possible solution to mitigate this race\n     * condition is to first reduce the spender's allowance to 0 and set the\n     * desired value afterwards:\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address spender, uint256 amount) external returns (bool);\n\n    /**\n     * @dev Moves `amount` tokens from `from` to `to` using the\n     * allowance mechanism. `amount` is then deducted from the caller's\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(address from, address to, uint256 amount) external returns (bool);\n}\n"
      },
      "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../IERC20.sol\";\nimport \"../extensions/IERC20Permit.sol\";\nimport \"../../../utils/Address.sol\";\n\n/**\n * @title SafeERC20\n * @dev Wrappers around ERC20 operations that throw on failure (when the token\n * contract returns false). Tokens that return no value (and instead revert or\n * throw on failure) are also supported, non-reverting calls are assumed to be\n * successful.\n * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,\n * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.\n */\nlibrary SafeERC20 {\n    using Address for address;\n\n    /**\n     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,\n     * non-reverting calls are assumed to be successful.\n     */\n    function safeTransfer(IERC20 token, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    /**\n     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the\n     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.\n     */\n    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));\n    }\n\n    /**\n     * @dev Deprecated. This function has issues similar to the ones found in\n     * {IERC20-approve}, and its usage is discouraged.\n     *\n     * Whenever possible, use {safeIncreaseAllowance} and\n     * {safeDecreaseAllowance} instead.\n     */\n    function safeApprove(IERC20 token, address spender, uint256 value) internal {\n        // safeApprove should only be called when setting an initial allowance,\n        // or when resetting it to zero. To increase and decrease it, use\n        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'\n        require(\n            (value == 0) || (token.allowance(address(this), spender) == 0),\n            \"SafeERC20: approve from non-zero to non-zero allowance\"\n        );\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));\n    }\n\n    /**\n     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,\n     * non-reverting calls are assumed to be successful.\n     */\n    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        uint256 oldAllowance = token.allowance(address(this), spender);\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));\n    }\n\n    /**\n     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,\n     * non-reverting calls are assumed to be successful.\n     */\n    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {\n        unchecked {\n            uint256 oldAllowance = token.allowance(address(this), spender);\n            require(oldAllowance >= value, \"SafeERC20: decreased allowance below zero\");\n            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));\n        }\n    }\n\n    /**\n     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,\n     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval\n     * to be set to zero before setting it to a non-zero value, such as USDT.\n     */\n    function forceApprove(IERC20 token, address spender, uint256 value) internal {\n        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);\n\n        if (!_callOptionalReturnBool(token, approvalCall)) {\n            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));\n            _callOptionalReturn(token, approvalCall);\n        }\n    }\n\n    /**\n     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.\n     * Revert on invalid signature.\n     */\n    function safePermit(\n        IERC20Permit token,\n        address owner,\n        address spender,\n        uint256 value,\n        uint256 deadline,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    ) internal {\n        uint256 nonceBefore = token.nonces(owner);\n        token.permit(owner, spender, value, deadline, v, r, s);\n        uint256 nonceAfter = token.nonces(owner);\n        require(nonceAfter == nonceBefore + 1, \"SafeERC20: permit did not succeed\");\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     */\n    function _callOptionalReturn(IERC20 token, bytes memory data) private {\n        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since\n        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that\n        // the target address contains contract code and also asserts for success in the low-level call.\n\n        bytes memory returndata = address(token).functionCall(data, \"SafeERC20: low-level call failed\");\n        require(returndata.length == 0 || abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n    }\n\n    /**\n     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement\n     * on the return value: the return value is optional (but if data is returned, it must not be false).\n     * @param token The token targeted by the call.\n     * @param data The call data (encoded using abi.encode or one of its variants).\n     *\n     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.\n     */\n    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {\n        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since\n        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false\n        // and not revert is the subcall reverts.\n\n        (bool success, bytes memory returndata) = address(token).call(data);\n        return\n            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));\n    }\n}\n"
      },
      "@openzeppelin/contracts/utils/Address.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)\n\npragma solidity ^0.8.1;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     *\n     * Furthermore, `isContract` will also return true if the target contract within\n     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,\n     * which only has an effect at the end of a transaction.\n     * ====\n     *\n     * [IMPORTANT]\n     * ====\n     * You shouldn't rely on `isContract` to protect against flash loan attacks!\n     *\n     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets\n     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract\n     * constructor.\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies on extcodesize/address.code.length, which returns 0\n        // for contracts in construction, since the code is only stored at the end\n        // of the constructor execution.\n\n        return account.code.length > 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance >= amount, \"Address: insufficient balance\");\n\n        (bool success, ) = recipient.call{value: amount}(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain `call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, 0, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(\n        address target,\n        bytes memory data,\n        uint256 value,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        require(address(this).balance >= value, \"Address: insufficient balance for call\");\n        (bool success, bytes memory returndata) = target.call{value: value}(data);\n        return verifyCallResultFromTarget(target, success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n        return functionStaticCall(target, data, \"Address: low-level static call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal view returns (bytes memory) {\n        (bool success, bytes memory returndata) = target.staticcall(data);\n        return verifyCallResultFromTarget(target, success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        (bool success, bytes memory returndata) = target.delegatecall(data);\n        return verifyCallResultFromTarget(target, success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling\n     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.\n     *\n     * _Available since v4.8._\n     */\n    function verifyCallResultFromTarget(\n        address target,\n        bool success,\n        bytes memory returndata,\n        string memory errorMessage\n    ) internal view returns (bytes memory) {\n        if (success) {\n            if (returndata.length == 0) {\n                // only check isContract if the call was successful and the return data is empty\n                // otherwise we already know that it was a contract\n                require(isContract(target), \"Address: call to non-contract\");\n            }\n            return returndata;\n        } else {\n            _revert(returndata, errorMessage);\n        }\n    }\n\n    /**\n     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the\n     * revert reason or using the provided one.\n     *\n     * _Available since v4.3._\n     */\n    function verifyCallResult(\n        bool success,\n        bytes memory returndata,\n        string memory errorMessage\n    ) internal pure returns (bytes memory) {\n        if (success) {\n            return returndata;\n        } else {\n            _revert(returndata, errorMessage);\n        }\n    }\n\n    function _revert(bytes memory returndata, string memory errorMessage) private pure {\n        // Look for revert reason and bubble it up if present\n        if (returndata.length > 0) {\n            // The easiest way to bubble the revert reason is using memory via assembly\n            /// @solidity memory-safe-assembly\n            assembly {\n                let returndata_size := mload(returndata)\n                revert(add(32, returndata), returndata_size)\n            }\n        } else {\n            revert(errorMessage);\n        }\n    }\n}\n"
      },
      "@openzeppelin/contracts/utils/Context.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.4) (utils/Context.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes calldata) {\n        return msg.data;\n    }\n\n    function _contextSuffixLength() internal view virtual returns (uint256) {\n        return 0;\n    }\n}\n"
      },
      "src/HotPotDevice/EventsAndErrors.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.20;\n\n/**\n * @title Events and errors for HotPot Device.\n */\nabstract contract EventsAndErrors {\n    /**\n     * The caller is not user.\n     */\n    error CallerIsNotUser();\n\n    /**\n     * Mint is not enabled.\n     */\n    error MintNotEnabled();\n\n    /**\n     * Maximum batch mint number exceeded.\n     */\n    error MaxBatchNumExceeded();\n\n    /**\n     * POT payment is not enabled.\n     */\n    error POTPaymentNotEnabled();\n\n    /**\n     * Token does not exist.\n     */\n    error TokenDoesNotExist();\n\n    /**\n     * Invalid params.\n     */\n    error InvalidParams();\n\n    /**\n     * Maximum supply exceeded.\n     */\n    error MaxSupplyExceeded();\n\n    /**\n     * Insufficient balance.\n     */\n    error InsufficientBalance();\n}\n"
      },
      "src/HotPotDevice/HotPotDevice.sol": {
        "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.8.20;\n\nimport {Ownable} from \"@openzeppelin/contracts/access/Ownable.sol\";\nimport {IERC20} from \"@openzeppelin/contracts/interfaces/IERC20.sol\";\nimport {SafeERC20} from \"@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol\";\n\nimport {EventsAndErrors} from \"./EventsAndErrors.sol\";\nimport {ERC721A} from \"./lib/erc721a/contracts/ERC721A.sol\";\n\n/**\n * @title HotPot device contract implementation.\n */\ncontract HotPotDevice is\n    Ownable,\n    ERC721A,\n    EventsAndErrors\n{\n    using SafeERC20 for IERC20;\n\n    // max supply\n    uint256 public constant MAX_SUPPLY = 20000;\n\n    // mint price in USDT\n    uint256 public priceUSDT;\n\n    // mint price in POT\n    uint256 public pricePOT;\n\n    // USDT\n    address public constant USDT = 0xdAC17F958D2ee523a2206206994597C13D831ec7;\n\n    // POT token\n    address public constant POT = 0x6a681AFA304aB6F19352715cCD0A0478Ee39f6fe;\n\n    // base token URI\n    string public baseURI;\n\n    // status\n    Status public status;\n\n    // maximum batch mint number\n    uint256 internal constant _maxBatchNum = 17;\n\n    // mapping token id to packed meta id\n    mapping(uint256 => uint256) internal _packedMetaIds;\n    \n    // random indices\n    uint256[MAX_SUPPLY] internal _randIndices;\n\n    // status pipeline\n    enum Status {\n        INIT,\n        OPEN,\n        PAUSED\n    }\n\n    // payment token type\n    enum PaymentType {\n        POT,\n        USDT\n    }\n\n    /**\n     * @notice Make sure that the caller is user.\n     */\n    modifier callerIsUser() {\n        if (tx.origin != _msgSender()) revert CallerIsNotUser();\n\n        _;\n    }\n\n    /**\n     * @notice Constructor.\n     * @param priceUSDT_  The price in USDT\n     * @param pricePOT_  The price in POT\n     * @param baseURI_  The base token URI\n     * @param status_ The initial status\n     */\n    constructor(\n        uint256 priceUSDT_,\n        uint256 pricePOT_,\n        string memory baseURI_,\n        Status status_\n    ) ERC721A(\"HotPot Device\", \"HotPotDevice\") {\n        priceUSDT = priceUSDT_;\n        pricePOT= pricePOT_;\n\n        baseURI = baseURI_;\n        status = status_;\n    }\n\n    /**\n     * @notice Mint tokens.\n     * @param quantity The quantity of tokens to be minted\n     * @param paymentType The type of the token used for payment\n     */\n    function mint(\n        uint256 quantity,\n        PaymentType paymentType\n    ) external callerIsUser {\n        if (status != Status.OPEN) revert MintNotEnabled();\n\n        _checkAndMint(_msgSender(), quantity, paymentType);\n    }\n\n    /**\n     * @notice Set the current status.\n     * @param status_ The current status\n     */\n    function setStatus(Status status_) external onlyOwner {\n        status = status_;\n    }\n\n    /**\n     * @notice Set the base token URI.\n     * @param baseURI_ The base token URI\n     */\n    function setBaseURI(string calldata baseURI_) external onlyOwner {\n        baseURI = baseURI_;\n    }\n\n    /**\n     * @notice Set the price in USDT.\n     * @param priceUSDT_ The price in USDT\n     */\n    function setPriceInUSDT(uint256 priceUSDT_) external onlyOwner {\n        priceUSDT = priceUSDT_;\n    }\n\n    /**\n     * @notice Set the price in POT.\n     * @param pricePOT_ The price in POT\n     */\n    function setPriceInPOT(uint256 pricePOT_) external onlyOwner {\n        pricePOT = pricePOT_;\n    }\n\n    /**\n     * @notice Withdraw balance by the specified token.\n     * @param token The target token\n     * @param to The recipient address\n     */\n    function withdraw(address token, address to) external onlyOwner {\n        uint256 balance = IERC20(token).balanceOf(address(this));\n        if (balance == 0) revert InsufficientBalance();\n\n        IERC20(token).safeTransfer(to, balance);\n    }\n\n    /**\n     * @notice Check and mint `quantity` of tokens to the specified account.\n     * @param to The specified recipient address\n     * @param quantity The quantity of tokens to be minted\n     * @param paymentType The type of the token used for payment\n     */\n    function _checkAndMint(\n        address to,\n        uint256 quantity,\n        PaymentType paymentType\n    ) internal {\n        if (quantity > _maxBatchNum) revert MaxBatchNumExceeded();\n        if (totalSupply() + quantity > MAX_SUPPLY) revert MaxSupplyExceeded();\n\n        _paymentHandler(to, quantity, paymentType);\n\n        _safeMint(to, quantity);\n        _setMetaIds(quantity);\n    }\n\n    /**\n     * @notice Handle payment.\n     * @param account The payment address\n     * @param quantity The quantity of tokens to be minted\n     * @param paymentType The type of the token used for payment\n     */\n    function _paymentHandler(\n        address account,\n        uint256 quantity,\n        PaymentType paymentType\n    ) internal {\n        if (paymentType == PaymentType.USDT) {\n            _paymentByToken(account, priceUSDT, quantity, IERC20(USDT));\n        } else {\n            if (pricePOT == 0) revert POTPaymentNotEnabled();\n\n            _paymentByToken(account, pricePOT, quantity, IERC20(POT));\n        }\n    }\n\n    /**\n     * @notice Handle payment by the given token.\n     * @param account The payment address\n     * @param price The unit price\n     * @param quantity The quantity of tokens to be minted\n     * @param paymentToken The type of the token used for payment\n     */\n    function _paymentByToken(\n        address account,\n        uint256 price,\n        uint256 quantity,\n        IERC20 paymentToken\n    ) internal {\n        uint256 totalPrice = price * quantity;\n\n        paymentToken.safeTransferFrom(account, address(this), totalPrice);\n    }\n\n    /**\n     * @notice Set the meta ids for the specified tokens.\n     * @param quantity The quantity of the tokens\n     */\n    function _setMetaIds(\n        uint256 quantity\n    ) internal {\n        uint256 preTotalMinted = _totalMinted() - quantity;\n        uint256 startTokenId = preTotalMinted + _startTokenId();\n\n        // set the meta id into the extra data for the starting token\n        _setExtraDataAt(startTokenId, uint24(_getRandomMetaId(preTotalMinted)));\n \n        if (quantity > 1) {\n             uint256 packedMetaId;\n\n            for(uint256 i = 1; i < quantity; i++) {\n                packedMetaId |= _getRandomMetaId(preTotalMinted + i) << (16 * (i - 1));\n            }\n\n            _packedMetaIds[startTokenId] = packedMetaId;\n        }\n    }\n\n    /**\n     * @notice Get the meta id of the given token.\n     * @param tokenId The id of the given token\n     * @return metaId The meta id of the given token\n     */\n    function _getMetaId(uint256 tokenId) internal view returns (uint256) {\n        uint256 metaId = _getMetaIdFromExtraData(tokenId);\n        if (metaId > 0 ) {\n            return metaId;\n        }\n\n        return _getMetaIdFromPackedMetaIds(tokenId);\n    }\n\n    /**\n     * @notice Get the meta id of the given token from the extra data\n     * @param tokenId The id of the given token\n     */\n    function _getMetaIdFromExtraData(uint256 tokenId) internal view returns (uint256) {\n        return _ownershipAt(tokenId).extraData;\n    }\n\n    /**\n     * @notice Get the meta id of the given token from the packed meta ids.\n     * @param tokenId The id of the given token\n     * @return metaId The meta id of the given token\n     */\n    function _getMetaIdFromPackedMetaIds(uint256 tokenId) internal view returns (uint256) {\n        uint256 index = _getPreNonEmptyExtraDataIndex(tokenId);\n\n        return uint16(_packedMetaIds[index] >> (16 * (tokenId - index - 1)));\n    }\n\n    /**\n     * @notice Override the super._startTokenId() implementation.\n     * @return startTokenId The starting id of tokens\n     */\n    function _startTokenId() internal view virtual override returns (uint256) {\n        return 1;\n    }\n\n    /**\n     * @notice See {IERC721Metadata-tokenURI}.\n     */\n    function tokenURI(\n        uint256 tokenId\n    ) public view virtual override returns (string memory) {\n        if (!_exists(tokenId)) revert TokenDoesNotExist();\n\n        return string.concat(baseURI, _toString(_getMetaId(tokenId)));\n    }\n\n    /**\n     * @notice Get the random meta id.\n     * @param totalMinted The total number of the minted tokens\n     * @return metaId Meta id\n     */\n    function _getRandomMetaId(uint256 totalMinted) internal returns (uint256) {\n        unchecked {\n            uint256 remain = MAX_SUPPLY - totalMinted;\n            uint256 pos = _getRandom(totalMinted) % remain;\n            uint256 val = _randIndices[pos] == 0 ? pos : _randIndices[pos];\n            _randIndices[pos] = _randIndices[remain - 1] == 0 ? remain - 1 : _randIndices[remain - 1];\n            \n            return val + 1;\n        }\n    }\n\n    /**\n     * @notice Generate a random number by on-chain randomness.\n     * @param totalMinted The total number of the minted tokens\n     * @return random Generated random number\n     */\n    function _getRandom(uint256 totalMinted) internal view returns (uint256) {\n        unchecked {\n            return uint256(keccak256(abi.encodePacked(\n                block.prevrandao,\n                block.coinbase,\n                totalMinted,\n                tx.origin\n            )));\n        }\n    }\n\n    /**\n     * @notice Get the index of the previous token which contains the non empty extra data.\n     * Note: This method always returns the expected result for the contract.\n     * @param tokenId The id of the given token\n     * @return index The index of the previous token which contains the non empty extra data\n     */\n    function _getPreNonEmptyExtraDataIndex(\n        uint256 tokenId\n    ) internal view returns (uint256) {\n        TokenOwnership memory ownership;\n\n        for (uint256 i = tokenId - 1; i >= _startTokenId(); i--) {\n            ownership = _ownershipAt(i);\n\n            if (ownership.extraData != 0) {\n                return i;\n            }\n        }\n\n        return 0; // never happen\n    }\n\n    /**\n     * @notice Query all tokens of the given owner.\n     * @param owner The owner\n     * @return tokenIds The ids of tokens of the owner\n     */\n    function tokensOfOwner(\n        address owner\n    ) external view returns (uint256[] memory) {\n        uint256 tokenIdsIdx;\n        address currOwnershipAddr;\n\n        uint256 tokenIdsLength = balanceOf(owner);\n        uint256[] memory tokenIds = new uint256[](tokenIdsLength);\n\n        TokenOwnership memory ownership;\n        for (uint256 i = _startTokenId(); tokenIdsIdx != tokenIdsLength; ++i) {\n            ownership = _ownershipAt(i);\n\n            if (ownership.burned) {\n                continue;\n            }\n\n            if (ownership.addr != address(0)) {\n                currOwnershipAddr = ownership.addr;\n            }\n\n            if (currOwnershipAddr == owner) {\n                tokenIds[tokenIdsIdx++] = i;\n            }\n        }\n\n        return tokenIds;\n    }\n}\n"
      },
      "src/HotPotDevice/lib/erc721a/contracts/ERC721A.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// ERC721A Contracts v4.2.3\n// Creator: Chiru Labs\n\npragma solidity ^0.8.4;\n\nimport './IERC721A.sol';\n\n/**\n * @dev Interface of ERC721 token receiver.\n */\ninterface ERC721A__IERC721Receiver {\n    function onERC721Received(\n        address operator,\n        address from,\n        uint256 tokenId,\n        bytes calldata data\n    ) external returns (bytes4);\n}\n\n/**\n * @title ERC721A\n *\n * @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)\n * Non-Fungible Token Standard, including the Metadata extension.\n * Optimized for lower gas during batch mints.\n *\n * Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)\n * starting from `_startTokenId()`.\n *\n * Assumptions:\n *\n * - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.\n * - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).\n */\ncontract ERC721A is IERC721A {\n    // Bypass for a `--via-ir` bug (https://github.com/chiru-labs/ERC721A/pull/364).\n    struct TokenApprovalRef {\n        address value;\n    }\n\n    // =============================================================\n    //                           CONSTANTS\n    // =============================================================\n\n    // Mask of an entry in packed address data.\n    uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;\n\n    // The bit position of `numberMinted` in packed address data.\n    uint256 private constant _BITPOS_NUMBER_MINTED = 64;\n\n    // The bit position of `numberBurned` in packed address data.\n    uint256 private constant _BITPOS_NUMBER_BURNED = 128;\n\n    // The bit position of `aux` in packed address data.\n    uint256 private constant _BITPOS_AUX = 192;\n\n    // Mask of all 256 bits in packed address data except the 64 bits for `aux`.\n    uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;\n\n    // The bit position of `startTimestamp` in packed ownership.\n    uint256 private constant _BITPOS_START_TIMESTAMP = 160;\n\n    // The bit mask of the `burned` bit in packed ownership.\n    uint256 private constant _BITMASK_BURNED = 1 << 224;\n\n    // The bit position of the `nextInitialized` bit in packed ownership.\n    uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;\n\n    // The bit mask of the `nextInitialized` bit in packed ownership.\n    uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;\n\n    // The bit position of `extraData` in packed ownership.\n    uint256 private constant _BITPOS_EXTRA_DATA = 232;\n\n    // Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.\n    uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;\n\n    // The mask of the lower 160 bits for addresses.\n    uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;\n\n    // The maximum `quantity` that can be minted with {_mintERC2309}.\n    // This limit is to prevent overflows on the address data entries.\n    // For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}\n    // is required to cause an overflow, which is unrealistic.\n    uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;\n\n    // The `Transfer` event signature is given by:\n    // `keccak256(bytes(\"Transfer(address,address,uint256)\"))`.\n    bytes32 private constant _TRANSFER_EVENT_SIGNATURE =\n        0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;\n\n    // =============================================================\n    //                            STORAGE\n    // =============================================================\n\n    // The next token ID to be minted.\n    uint256 private _currentIndex;\n\n    // The number of tokens burned.\n    uint256 private _burnCounter;\n\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Mapping from token ID to ownership details\n    // An empty struct value does not necessarily mean the token is unowned.\n    // See {_packedOwnershipOf} implementation for details.\n    //\n    // Bits Layout:\n    // - [0..159]   `addr`\n    // - [160..223] `startTimestamp`\n    // - [224]      `burned`\n    // - [225]      `nextInitialized`\n    // - [232..255] `extraData`\n    mapping(uint256 => uint256) private _packedOwnerships;\n\n    // Mapping owner address to address data.\n    //\n    // Bits Layout:\n    // - [0..63]    `balance`\n    // - [64..127]  `numberMinted`\n    // - [128..191] `numberBurned`\n    // - [192..255] `aux`\n    mapping(address => uint256) private _packedAddressData;\n\n    // Mapping from token ID to approved address.\n    mapping(uint256 => TokenApprovalRef) private _tokenApprovals;\n\n    // Mapping from owner to operator approvals\n    mapping(address => mapping(address => bool)) private _operatorApprovals;\n\n    // =============================================================\n    //                          CONSTRUCTOR\n    // =============================================================\n\n    constructor(string memory name_, string memory symbol_) {\n        _name = name_;\n        _symbol = symbol_;\n        _currentIndex = _startTokenId();\n    }\n\n    // =============================================================\n    //                   TOKEN COUNTING OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Returns the starting token ID.\n     * To change the starting token ID, please override this function.\n     */\n    function _startTokenId() internal view virtual returns (uint256) {\n        return 0;\n    }\n\n    /**\n     * @dev Returns the next token ID to be minted.\n     */\n    function _nextTokenId() internal view virtual returns (uint256) {\n        return _currentIndex;\n    }\n\n    /**\n     * @dev Returns the total number of tokens in existence.\n     * Burned tokens will reduce the count.\n     * To get the total number of tokens minted, please see {_totalMinted}.\n     */\n    function totalSupply() public view virtual override returns (uint256) {\n        // Counter underflow is impossible as _burnCounter cannot be incremented\n        // more than `_currentIndex - _startTokenId()` times.\n        unchecked {\n            return _currentIndex - _burnCounter - _startTokenId();\n        }\n    }\n\n    /**\n     * @dev Returns the total amount of tokens minted in the contract.\n     */\n    function _totalMinted() internal view virtual returns (uint256) {\n        // Counter underflow is impossible as `_currentIndex` does not decrement,\n        // and it is initialized to `_startTokenId()`.\n        unchecked {\n            return _currentIndex - _startTokenId();\n        }\n    }\n\n    /**\n     * @dev Returns the total number of tokens burned.\n     */\n    function _totalBurned() internal view virtual returns (uint256) {\n        return _burnCounter;\n    }\n\n    // =============================================================\n    //                    ADDRESS DATA OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Returns the number of tokens in `owner`'s account.\n     */\n    function balanceOf(address owner) public view virtual override returns (uint256) {\n        if (owner == address(0)) revert BalanceQueryForZeroAddress();\n        return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;\n    }\n\n    /**\n     * Returns the number of tokens minted by `owner`.\n     */\n    function _numberMinted(address owner) internal view returns (uint256) {\n        return (_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;\n    }\n\n    /**\n     * Returns the number of tokens burned by or on behalf of `owner`.\n     */\n    function _numberBurned(address owner) internal view returns (uint256) {\n        return (_packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) & _BITMASK_ADDRESS_DATA_ENTRY;\n    }\n\n    /**\n     * Returns the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).\n     */\n    function _getAux(address owner) internal view returns (uint64) {\n        return uint64(_packedAddressData[owner] >> _BITPOS_AUX);\n    }\n\n    /**\n     * Sets the auxiliary data for `owner`. (e.g. number of whitelist mint slots used).\n     * If there are multiple variables, please pack them into a uint64.\n     */\n    function _setAux(address owner, uint64 aux) internal virtual {\n        uint256 packed = _packedAddressData[owner];\n        uint256 auxCasted;\n        // Cast `aux` with assembly to avoid redundant masking.\n        assembly {\n            auxCasted := aux\n        }\n        packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);\n        _packedAddressData[owner] = packed;\n    }\n\n    // =============================================================\n    //                            IERC165\n    // =============================================================\n\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n        // The interface IDs are constants representing the first 4 bytes\n        // of the XOR of all function selectors in the interface.\n        // See: [ERC165](https://eips.ethereum.org/EIPS/eip-165)\n        // (e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`)\n        return\n            interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.\n            interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.\n            interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.\n    }\n\n    // =============================================================\n    //                        IERC721Metadata\n    // =============================================================\n\n    /**\n     * @dev Returns the token collection name.\n     */\n    function name() public view virtual override returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Returns the token collection symbol.\n     */\n    function symbol() public view virtual override returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.\n     */\n    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {\n        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();\n\n        string memory baseURI = _baseURI();\n        return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : '';\n    }\n\n    /**\n     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each\n     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty\n     * by default, it can be overridden in child contracts.\n     */\n    function _baseURI() internal view virtual returns (string memory) {\n        return '';\n    }\n\n    // =============================================================\n    //                     OWNERSHIPS OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Returns the owner of the `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function ownerOf(uint256 tokenId) public view virtual override returns (address) {\n        return address(uint160(_packedOwnershipOf(tokenId)));\n    }\n\n    /**\n     * @dev Gas spent here starts off proportional to the maximum mint batch size.\n     * It gradually moves to O(1) as tokens get transferred around over time.\n     */\n    function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {\n        return _unpackedOwnership(_packedOwnershipOf(tokenId));\n    }\n\n    /**\n     * @dev Returns the unpacked `TokenOwnership` struct at `index`.\n     */\n    function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {\n        return _unpackedOwnership(_packedOwnerships[index]);\n    }\n\n    /**\n     * @dev Initializes the ownership slot minted at `index` for efficiency purposes.\n     */\n    function _initializeOwnershipAt(uint256 index) internal virtual {\n        if (_packedOwnerships[index] == 0) {\n            _packedOwnerships[index] = _packedOwnershipOf(index);\n        }\n    }\n\n    /**\n     * Returns the packed ownership data of `tokenId`.\n     */\n    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {\n        uint256 curr = tokenId;\n\n        unchecked {\n            if (_startTokenId() <= curr)\n                if (curr < _currentIndex) {\n                    uint256 packed = _packedOwnerships[curr];\n                    // If not burned.\n                    if (packed & _BITMASK_BURNED == 0) {\n                        // Invariant:\n                        // There will always be an initialized ownership slot\n                        // (i.e. `ownership.addr != address(0) && ownership.burned == false`)\n                        // before an unintialized ownership slot\n                        // (i.e. `ownership.addr == address(0) && ownership.burned == false`)\n                        // Hence, `curr` will not underflow.\n                        //\n                        // We can directly compare the packed value.\n                        // If the address is zero, packed will be zero.\n                        while (packed == 0) {\n                            packed = _packedOwnerships[--curr];\n                        }\n                        return packed;\n                    }\n                }\n        }\n        revert OwnerQueryForNonexistentToken();\n    }\n\n    /**\n     * @dev Returns the unpacked `TokenOwnership` struct from `packed`.\n     */\n    function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {\n        ownership.addr = address(uint160(packed));\n        ownership.startTimestamp = uint64(packed >> _BITPOS_START_TIMESTAMP);\n        ownership.burned = packed & _BITMASK_BURNED != 0;\n        ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);\n    }\n\n    /**\n     * @dev Packs ownership data into a single uint256.\n     */\n    function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {\n        assembly {\n            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.\n            owner := and(owner, _BITMASK_ADDRESS)\n            // `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.\n            result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))\n        }\n    }\n\n    /**\n     * @dev Returns the `nextInitialized` flag set if `quantity` equals 1.\n     */\n    function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {\n        // For branchless setting of the `nextInitialized` flag.\n        assembly {\n            // `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.\n            result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))\n        }\n    }\n\n    // =============================================================\n    //                      APPROVAL OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\n     * The approval is cleared when the token is transferred.\n     *\n     * Only a single account can be approved at a time, so approving the\n     * zero address clears previous approvals.\n     *\n     * Requirements:\n     *\n     * - The caller must own the token or be an approved operator.\n     * - `tokenId` must exist.\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address to, uint256 tokenId) public payable virtual override {\n        address owner = ownerOf(tokenId);\n\n        if (_msgSenderERC721A() != owner)\n            if (!isApprovedForAll(owner, _msgSenderERC721A())) {\n                revert ApprovalCallerNotOwnerNorApproved();\n            }\n\n        _tokenApprovals[tokenId].value = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Returns the account approved for `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function getApproved(uint256 tokenId) public view virtual override returns (address) {\n        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();\n\n        return _tokenApprovals[tokenId].value;\n    }\n\n    /**\n     * @dev Approve or remove `operator` as an operator for the caller.\n     * Operators can call {transferFrom} or {safeTransferFrom}\n     * for any token owned by the caller.\n     *\n     * Requirements:\n     *\n     * - The `operator` cannot be the caller.\n     *\n     * Emits an {ApprovalForAll} event.\n     */\n    function setApprovalForAll(address operator, bool approved) public virtual override {\n        _operatorApprovals[_msgSenderERC721A()][operator] = approved;\n        emit ApprovalForAll(_msgSenderERC721A(), operator, approved);\n    }\n\n    /**\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\n     *\n     * See {setApprovalForAll}.\n     */\n    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev Returns whether `tokenId` exists.\n     *\n     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.\n     *\n     * Tokens start existing when they are minted. See {_mint}.\n     */\n    function _exists(uint256 tokenId) internal view virtual returns (bool) {\n        return\n            _startTokenId() <= tokenId &&\n            tokenId < _currentIndex && // If within bounds,\n            _packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.\n    }\n\n    /**\n     * @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.\n     */\n    function _isSenderApprovedOrOwner(\n        address approvedAddress,\n        address owner,\n        address msgSender\n    ) private pure returns (bool result) {\n        assembly {\n            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.\n            owner := and(owner, _BITMASK_ADDRESS)\n            // Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.\n            msgSender := and(msgSender, _BITMASK_ADDRESS)\n            // `msgSender == owner || msgSender == approvedAddress`.\n            result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))\n        }\n    }\n\n    /**\n     * @dev Returns the storage slot and value for the approved address of `tokenId`.\n     */\n    function _getApprovedSlotAndAddress(uint256 tokenId)\n        private\n        view\n        returns (uint256 approvedAddressSlot, address approvedAddress)\n    {\n        TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];\n        // The following is equivalent to `approvedAddress = _tokenApprovals[tokenId].value`.\n        assembly {\n            approvedAddressSlot := tokenApproval.slot\n            approvedAddress := sload(approvedAddressSlot)\n        }\n    }\n\n    // =============================================================\n    //                      TRANSFER OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Transfers `tokenId` from `from` to `to`.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token\n     * by either {approve} or {setApprovalForAll}.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) public payable virtual override {\n        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);\n\n        if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();\n\n        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);\n\n        // The nested ifs save around 20+ gas over a compound boolean condition.\n        if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))\n            if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();\n\n        if (to == address(0)) revert TransferToZeroAddress();\n\n        _beforeTokenTransfers(from, to, tokenId, 1);\n\n        // Clear approvals from the previous owner.\n        assembly {\n            if approvedAddress {\n                // This is equivalent to `delete _tokenApprovals[tokenId]`.\n                sstore(approvedAddressSlot, 0)\n            }\n        }\n\n        // Underflow of the sender's balance is impossible because we check for\n        // ownership above and the recipient's balance can't realistically overflow.\n        // Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.\n        unchecked {\n            // We can directly increment and decrement the balances.\n            --_packedAddressData[from]; // Updates: `balance -= 1`.\n            ++_packedAddressData[to]; // Updates: `balance += 1`.\n\n            // Updates:\n            // - `address` to the next owner.\n            // - `startTimestamp` to the timestamp of transfering.\n            // - `burned` to `false`.\n            // - `nextInitialized` to `true`.\n            _packedOwnerships[tokenId] = _packOwnershipData(\n                to,\n                _BITMASK_NEXT_INITIALIZED | _nextExtraData_Ex(from, to, prevOwnershipPacked, _packedOwnerships[tokenId] != 0)\n            );\n\n            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .\n            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {\n                uint256 nextTokenId = tokenId + 1;\n                // If the next slot's address is zero and not burned (i.e. packed value is zero).\n                if (_packedOwnerships[nextTokenId] == 0) {\n                    // If the next slot is within bounds.\n                    if (nextTokenId != _currentIndex) {\n                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.\n                        _packedOwnerships[nextTokenId] = (prevOwnershipPacked & _BITMASK_EXTRA_DATA_COMPLEMENT) | (uint24(0) << _BITPOS_EXTRA_DATA);\n                    }\n                }\n            }\n        }\n\n        emit Transfer(from, to, tokenId);\n        _afterTokenTransfers(from, to, tokenId, 1);\n    }\n\n    /**\n     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) public payable virtual override {\n        safeTransferFrom(from, to, tokenId, '');\n    }\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token\n     * by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement\n     * {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) public payable virtual override {\n        transferFrom(from, to, tokenId);\n        if (to.code.length != 0)\n            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {\n                revert TransferToNonERC721ReceiverImplementer();\n            }\n    }\n\n    /**\n     * @dev Hook that is called before a set of serially-ordered token IDs\n     * are about to be transferred. This includes minting.\n     * And also called before burning one token.\n     *\n     * `startTokenId` - the first token ID to be transferred.\n     * `quantity` - the amount to be transferred.\n     *\n     * Calling conditions:\n     *\n     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be\n     * transferred to `to`.\n     * - When `from` is zero, `tokenId` will be minted for `to`.\n     * - When `to` is zero, `tokenId` will be burned by `from`.\n     * - `from` and `to` are never both zero.\n     */\n    function _beforeTokenTransfers(\n        address from,\n        address to,\n        uint256 startTokenId,\n        uint256 quantity\n    ) internal virtual {}\n\n    /**\n     * @dev Hook that is called after a set of serially-ordered token IDs\n     * have been transferred. This includes minting.\n     * And also called after one token has been burned.\n     *\n     * `startTokenId` - the first token ID to be transferred.\n     * `quantity` - the amount to be transferred.\n     *\n     * Calling conditions:\n     *\n     * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been\n     * transferred to `to`.\n     * - When `from` is zero, `tokenId` has been minted for `to`.\n     * - When `to` is zero, `tokenId` has been burned by `from`.\n     * - `from` and `to` are never both zero.\n     */\n    function _afterTokenTransfers(\n        address from,\n        address to,\n        uint256 startTokenId,\n        uint256 quantity\n    ) internal virtual {}\n\n    /**\n     * @dev Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.\n     *\n     * `from` - Previous owner of the given token ID.\n     * `to` - Target address that will receive the token.\n     * `tokenId` - Token ID to be transferred.\n     * `_data` - Optional data to send along with the call.\n     *\n     * Returns whether the call correctly returned the expected magic value.\n     */\n    function _checkContractOnERC721Received(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) private returns (bool) {\n        try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (\n            bytes4 retval\n        ) {\n            return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;\n        } catch (bytes memory reason) {\n            if (reason.length == 0) {\n                revert TransferToNonERC721ReceiverImplementer();\n            } else {\n                assembly {\n                    revert(add(32, reason), mload(reason))\n                }\n            }\n        }\n    }\n\n    // =============================================================\n    //                        MINT OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Mints `quantity` tokens and transfers them to `to`.\n     *\n     * Requirements:\n     *\n     * - `to` cannot be the zero address.\n     * - `quantity` must be greater than 0.\n     *\n     * Emits a {Transfer} event for each mint.\n     */\n    function _mint(address to, uint256 quantity) internal virtual {\n        uint256 startTokenId = _currentIndex;\n        if (quantity == 0) revert MintZeroQuantity();\n\n        _beforeTokenTransfers(address(0), to, startTokenId, quantity);\n\n        // Overflows are incredibly unrealistic.\n        // `balance` and `numberMinted` have a maximum limit of 2**64.\n        // `tokenId` has a maximum limit of 2**256.\n        unchecked {\n            // Updates:\n            // - `balance += quantity`.\n            // - `numberMinted += quantity`.\n            //\n            // We can directly add to the `balance` and `numberMinted`.\n            _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);\n\n            // Updates:\n            // - `address` to the owner.\n            // - `startTimestamp` to the timestamp of minting.\n            // - `burned` to `false`.\n            // - `nextInitialized` to `quantity == 1`.\n            _packedOwnerships[startTokenId] = _packOwnershipData(\n                to,\n                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)\n            );\n\n            uint256 toMasked;\n            uint256 end = startTokenId + quantity;\n\n            // Use assembly to loop and emit the `Transfer` event for gas savings.\n            // The duplicated `log4` removes an extra check and reduces stack juggling.\n            // The assembly, together with the surrounding Solidity code, have been\n            // delicately arranged to nudge the compiler into producing optimized opcodes.\n            assembly {\n                // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.\n                toMasked := and(to, _BITMASK_ADDRESS)\n                // Emit the `Transfer` event.\n                log4(\n                    0, // Start of data (0, since no data).\n                    0, // End of data (0, since no data).\n                    _TRANSFER_EVENT_SIGNATURE, // Signature.\n                    0, // `address(0)`.\n                    toMasked, // `to`.\n                    startTokenId // `tokenId`.\n                )\n\n                // The `iszero(eq(,))` check ensures that large values of `quantity`\n                // that overflows uint256 will make the loop run out of gas.\n                // The compiler will optimize the `iszero` away for performance.\n                for {\n                    let tokenId := add(startTokenId, 1)\n                } iszero(eq(tokenId, end)) {\n                    tokenId := add(tokenId, 1)\n                } {\n                    // Emit the `Transfer` event. Similar to above.\n                    log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)\n                }\n            }\n            if (toMasked == 0) revert MintToZeroAddress();\n\n            _currentIndex = end;\n        }\n        _afterTokenTransfers(address(0), to, startTokenId, quantity);\n    }\n\n    /**\n     * @dev Mints `quantity` tokens and transfers them to `to`.\n     *\n     * This function is intended for efficient minting only during contract creation.\n     *\n     * It emits only one {ConsecutiveTransfer} as defined in\n     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),\n     * instead of a sequence of {Transfer} event(s).\n     *\n     * Calling this function outside of contract creation WILL make your contract\n     * non-compliant with the ERC721 standard.\n     * For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309\n     * {ConsecutiveTransfer} event is only permissible during contract creation.\n     *\n     * Requirements:\n     *\n     * - `to` cannot be the zero address.\n     * - `quantity` must be greater than 0.\n     *\n     * Emits a {ConsecutiveTransfer} event.\n     */\n    function _mintERC2309(address to, uint256 quantity) internal virtual {\n        uint256 startTokenId = _currentIndex;\n        if (to == address(0)) revert MintToZeroAddress();\n        if (quantity == 0) revert MintZeroQuantity();\n        if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();\n\n        _beforeTokenTransfers(address(0), to, startTokenId, quantity);\n\n        // Overflows are unrealistic due to the above check for `quantity` to be below the limit.\n        unchecked {\n            // Updates:\n            // - `balance += quantity`.\n            // - `numberMinted += quantity`.\n            //\n            // We can directly add to the `balance` and `numberMinted`.\n            _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);\n\n            // Updates:\n            // - `address` to the owner.\n            // - `startTimestamp` to the timestamp of minting.\n            // - `burned` to `false`.\n            // - `nextInitialized` to `quantity == 1`.\n            _packedOwnerships[startTokenId] = _packOwnershipData(\n                to,\n                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)\n            );\n\n            emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);\n\n            _currentIndex = startTokenId + quantity;\n        }\n        _afterTokenTransfers(address(0), to, startTokenId, quantity);\n    }\n\n    /**\n     * @dev Safely mints `quantity` tokens and transfers them to `to`.\n     *\n     * Requirements:\n     *\n     * - If `to` refers to a smart contract, it must implement\n     * {IERC721Receiver-onERC721Received}, which is called for each safe transfer.\n     * - `quantity` must be greater than 0.\n     *\n     * See {_mint}.\n     *\n     * Emits a {Transfer} event for each mint.\n     */\n    function _safeMint(\n        address to,\n        uint256 quantity,\n        bytes memory _data\n    ) internal virtual {\n        _mint(to, quantity);\n\n        unchecked {\n            if (to.code.length != 0) {\n                uint256 end = _currentIndex;\n                uint256 index = end - quantity;\n                do {\n                    if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {\n                        revert TransferToNonERC721ReceiverImplementer();\n                    }\n                } while (index < end);\n                // Reentrancy protection.\n                if (_currentIndex != end) revert();\n            }\n        }\n    }\n\n    /**\n     * @dev Equivalent to `_safeMint(to, quantity, '')`.\n     */\n    function _safeMint(address to, uint256 quantity) internal virtual {\n        _safeMint(to, quantity, '');\n    }\n\n    // =============================================================\n    //                        BURN OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Equivalent to `_burn(tokenId, false)`.\n     */\n    function _burn(uint256 tokenId) internal virtual {\n        _burn(tokenId, false);\n    }\n\n    /**\n     * @dev Destroys `tokenId`.\n     * The approval is cleared when the token is burned.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _burn(uint256 tokenId, bool approvalCheck) internal virtual {\n        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);\n\n        address from = address(uint160(prevOwnershipPacked));\n\n        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);\n\n        if (approvalCheck) {\n            // The nested ifs save around 20+ gas over a compound boolean condition.\n            if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))\n                if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();\n        }\n\n        _beforeTokenTransfers(from, address(0), tokenId, 1);\n\n        // Clear approvals from the previous owner.\n        assembly {\n            if approvedAddress {\n                // This is equivalent to `delete _tokenApprovals[tokenId]`.\n                sstore(approvedAddressSlot, 0)\n            }\n        }\n\n        // Underflow of the sender's balance is impossible because we check for\n        // ownership above and the recipient's balance can't realistically overflow.\n        // Counter overflow is incredibly unrealistic as `tokenId` would have to be 2**256.\n        unchecked {\n            // Updates:\n            // - `balance -= 1`.\n            // - `numberBurned += 1`.\n            //\n            // We can directly decrement the balance, and increment the number burned.\n            // This is equivalent to `packed -= 1; packed += 1 << _BITPOS_NUMBER_BURNED;`.\n            _packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;\n\n            // Updates:\n            // - `address` to the last owner.\n            // - `startTimestamp` to the timestamp of burning.\n            // - `burned` to `true`.\n            // - `nextInitialized` to `true`.\n            _packedOwnerships[tokenId] = _packOwnershipData(\n                from,\n                (_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData_Ex(from, address(0), prevOwnershipPacked, _packedOwnerships[tokenId] != 0)\n            );\n\n            // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .\n            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {\n                uint256 nextTokenId = tokenId + 1;\n                // If the next slot's address is zero and not burned (i.e. packed value is zero).\n                if (_packedOwnerships[nextTokenId] == 0) {\n                    // If the next slot is within bounds.\n                    if (nextTokenId != _currentIndex) {\n                        // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.\n                        _packedOwnerships[nextTokenId] = (prevOwnershipPacked & _BITMASK_EXTRA_DATA_COMPLEMENT) | (uint24(0) << _BITPOS_EXTRA_DATA);\n                    }\n                }\n            }\n        }\n\n        emit Transfer(from, address(0), tokenId);\n        _afterTokenTransfers(from, address(0), tokenId, 1);\n\n        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.\n        unchecked {\n            _burnCounter++;\n        }\n    }\n\n    // =============================================================\n    //                     EXTRA DATA OPERATIONS\n    // =============================================================\n\n    /**_packedOwnerships\n     * @dev Directly sets the extra data for the ownership data `index`.\n     */\n    function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {\n        uint256 packed = _packedOwnerships[index];\n        // Assume this always holds\n        // if (packed == 0) revert OwnershipNotInitializedForExtraData();\n        uint256 extraDataCasted;\n        // Cast `extraData` with assembly to avoid redundant masking.\n        assembly {\n            extraDataCasted := extraData\n        }\n        packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);\n        _packedOwnerships[index] = packed;\n    }\n\n    /**\n     * @dev Called during each token transfer to set the 24bit `extraData` field.\n     * Intended to be overridden by the cosumer contract.\n     *\n     * `previousExtraData` - the value of `extraData` before transfer.\n     *\n     * Calling conditions:\n     *\n     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be\n     * transferred to `to`.\n     * - When `from` is zero, `tokenId` will be minted for `to`.\n     * - When `to` is zero, `tokenId` will be burned by `from`.\n     * - `from` and `to` are never both zero.\n     */\n    function _extraData(\n        address from,\n        address to,\n        uint24 previousExtraData\n    ) internal view virtual returns (uint24) {\n        return previousExtraData;\n    }\n\n    /**\n     * @dev Called during each token transfer to set the 24bit `extraData` field.\n     * Intended to be overridden by the cosumer contract.\n     *\n     * `previousExtraData` - the value of `extraData` before transfer.\n     *\n     * Calling conditions:\n     *\n     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be\n     * transferred to `to`.\n     * - When `from` is zero, `tokenId` will be minted for `to`.\n     * - When `to` is zero, `tokenId` will be burned by `from`.\n     * - `from` and `to` are never both zero.\n     */\n    function _extraData_Ex(\n        address from,\n        address to,\n        uint24 previousExtraData,\n        bool initialized\n    ) internal view virtual returns (uint24) {\n        return initialized ? previousExtraData : 0;\n    }\n\n    /**\n     * @dev Returns the next extra data for the packed ownership data.\n     * The returned result is shifted into position.\n     */\n    function _nextExtraData(\n        address from,\n        address to,\n        uint256 prevOwnershipPacked\n    ) private view returns (uint256) {\n        uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);\n        return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;\n    }\n\n    /**\n     * @dev Returns the next extra data for the packed ownership data.\n     * The returned result is shifted into position.\n     */\n    function _nextExtraData_Ex(\n        address from,\n        address to,\n        uint256 prevOwnershipPacked,\n        bool initialized\n    ) private view returns (uint256) {\n        uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);\n        return uint256(_extraData_Ex(from, to, extraData, initialized)) << _BITPOS_EXTRA_DATA;\n    }\n\n    // =============================================================\n    //                       OTHER OPERATIONS\n    // =============================================================\n\n    /**\n     * @dev Returns the message sender (defaults to `msg.sender`).\n     *\n     * If you are writing GSN compatible contracts, you need to override this function.\n     */\n    function _msgSenderERC721A() internal view virtual returns (address) {\n        return msg.sender;\n    }\n\n    /**\n     * @dev Converts a uint256 to its ASCII string decimal representation.\n     */\n    function _toString(uint256 value) internal pure virtual returns (string memory str) {\n        assembly {\n            // The maximum value of a uint256 contains 78 digits (1 byte per digit), but\n            // we allocate 0xa0 bytes to keep the free memory pointer 32-byte word aligned.\n            // We will need 1 word for the trailing zeros padding, 1 word for the length,\n            // and 3 words for a maximum of 78 digits. Total: 5 * 0x20 = 0xa0.\n            let m := add(mload(0x40), 0xa0)\n            // Update the free memory pointer to allocate.\n            mstore(0x40, m)\n            // Assign the `str` to the end.\n            str := sub(m, 0x20)\n            // Zeroize the slot after the string.\n            mstore(str, 0)\n\n            // Cache the end of the memory to calculate the length later.\n            let end := str\n\n            // We write the string from rightmost digit to leftmost digit.\n            // The following is essentially a do-while loop that also handles the zero case.\n            // prettier-ignore\n            for { let temp := value } 1 {} {\n                str := sub(str, 1)\n                // Write the character to the pointer.\n                // The ASCII index of the '0' character is 48.\n                mstore8(str, add(48, mod(temp, 10)))\n                // Keep dividing `temp` until zero.\n                temp := div(temp, 10)\n                // prettier-ignore\n                if iszero(temp) { break }\n            }\n\n            let length := sub(end, str)\n            // Move the pointer 32 bytes leftwards to make room for the length.\n            str := sub(str, 0x20)\n            // Store the length.\n            mstore(str, length)\n        }\n    }\n}\n"
      },
      "src/HotPotDevice/lib/erc721a/contracts/IERC721A.sol": {
        "content": "// SPDX-License-Identifier: MIT\n// ERC721A Contracts v4.2.3\n// Creator: Chiru Labs\n\npragma solidity ^0.8.4;\n\n/**\n * @dev Interface of ERC721A.\n */\ninterface IERC721A {\n    /**\n     * The caller must own the token or be an approved operator.\n     */\n    error ApprovalCallerNotOwnerNorApproved();\n\n    /**\n     * The token does not exist.\n     */\n    error ApprovalQueryForNonexistentToken();\n\n    /**\n     * Cannot query the balance for the zero address.\n     */\n    error BalanceQueryForZeroAddress();\n\n    /**\n     * Cannot mint to the zero address.\n     */\n    error MintToZeroAddress();\n\n    /**\n     * The quantity of tokens minted must be more than zero.\n     */\n    error MintZeroQuantity();\n\n    /**\n     * The token does not exist.\n     */\n    error OwnerQueryForNonexistentToken();\n\n    /**\n     * The caller must own the token or be an approved operator.\n     */\n    error TransferCallerNotOwnerNorApproved();\n\n    /**\n     * The token must be owned by `from`.\n     */\n    error TransferFromIncorrectOwner();\n\n    /**\n     * Cannot safely transfer to a contract that does not implement the\n     * ERC721Receiver interface.\n     */\n    error TransferToNonERC721ReceiverImplementer();\n\n    /**\n     * Cannot transfer to the zero address.\n     */\n    error TransferToZeroAddress();\n\n    /**\n     * The token does not exist.\n     */\n    error URIQueryForNonexistentToken();\n\n    /**\n     * The `quantity` minted with ERC2309 exceeds the safety limit.\n     */\n    error MintERC2309QuantityExceedsLimit();\n\n    /**\n     * The `extraData` cannot be set on an unintialized ownership slot.\n     */\n    error OwnershipNotInitializedForExtraData();\n\n    // =============================================================\n    //                            STRUCTS\n    // =============================================================\n\n    struct TokenOwnership {\n        // The address of the owner.\n        address addr;\n        // Stores the start time of ownership with minimal overhead for tokenomics.\n        uint64 startTimestamp;\n        // Whether the token has been burned.\n        bool burned;\n        // Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.\n        uint24 extraData;\n    }\n\n    // =============================================================\n    //                         TOKEN COUNTERS\n    // =============================================================\n\n    /**\n     * @dev Returns the total number of tokens in existence.\n     * Burned tokens will reduce the count.\n     * To get the total number of tokens minted, please see {_totalMinted}.\n     */\n    function totalSupply() external view returns (uint256);\n\n    // =============================================================\n    //                            IERC165\n    // =============================================================\n\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n\n    // =============================================================\n    //                            IERC721\n    // =============================================================\n\n    /**\n     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\n     */\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables or disables\n     * (`approved`) `operator` to manage all of its assets.\n     */\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of tokens in `owner`'s account.\n     */\n    function balanceOf(address owner) external view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function ownerOf(uint256 tokenId) external view returns (address owner);\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`,\n     * checking first that contract recipients are aware of the ERC721 protocol\n     * to prevent tokens from being forever locked.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move\n     * this token by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement\n     * {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes calldata data\n    ) external payable;\n\n    /**\n     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external payable;\n\n    /**\n     * @dev Transfers `tokenId` from `from` to `to`.\n     *\n     * WARNING: Usage of this method is discouraged, use {safeTransferFrom}\n     * whenever possible.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token\n     * by either {approve} or {setApprovalForAll}.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external payable;\n\n    /**\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\n     * The approval is cleared when the token is transferred.\n     *\n     * Only a single account can be approved at a time, so approving the\n     * zero address clears previous approvals.\n     *\n     * Requirements:\n     *\n     * - The caller must own the token or be an approved operator.\n     * - `tokenId` must exist.\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address to, uint256 tokenId) external payable;\n\n    /**\n     * @dev Approve or remove `operator` as an operator for the caller.\n     * Operators can call {transferFrom} or {safeTransferFrom}\n     * for any token owned by the caller.\n     *\n     * Requirements:\n     *\n     * - The `operator` cannot be the caller.\n     *\n     * Emits an {ApprovalForAll} event.\n     */\n    function setApprovalForAll(address operator, bool _approved) external;\n\n    /**\n     * @dev Returns the account approved for `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function getApproved(uint256 tokenId) external view returns (address operator);\n\n    /**\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\n     *\n     * See {setApprovalForAll}.\n     */\n    function isApprovedForAll(address owner, address operator) external view returns (bool);\n\n    // =============================================================\n    //                        IERC721Metadata\n    // =============================================================\n\n    /**\n     * @dev Returns the token collection name.\n     */\n    function name() external view returns (string memory);\n\n    /**\n     * @dev Returns the token collection symbol.\n     */\n    function symbol() external view returns (string memory);\n\n    /**\n     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n\n    // =============================================================\n    //                           IERC2309\n    // =============================================================\n\n    /**\n     * @dev Emitted when tokens in `fromTokenId` to `toTokenId`\n     * (inclusive) is transferred from `from` to `to`, as defined in the\n     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.\n     *\n     * See {_mintERC2309} for more details.\n     */\n    event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);\n}\n"
      }
    },
    "settings": {
      "optimizer": {
        "enabled": true,
        "runs": 200
      },
      "evmVersion": "shanghai",
      "outputSelection": {
        "*": {
          "*": [
            "evm.bytecode",
            "evm.deployedBytecode",
            "abi"
          ]
        }
      }
    }
  }}