contract UpgradeableClaimable is Initializable, Context {
    address private _owner;
    address private _pendingOwner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting a custom initial owner of choice.
     * @param __owner Initial owner of contract to be set.
     */
    function initialize(address __owner) internal initializer {
        _owner = __owner;
        emit OwnershipTransferred(address(0), __owner);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Returns the address of the pending owner.
     */
    function pendingOwner() public view returns (address) {
        return _pendingOwner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Modifier throws if called by any account other than the pendingOwner.
     */
    modifier onlyPendingOwner() {
        require(msg.sender == _pendingOwner, "Ownable: caller is not the pending owner");
        _;
    }

    /**
     * @dev Allows the current owner to set the pendingOwner address.
     * @param newOwner The address to transfer ownership to.
     */
    function transferOwnership(address newOwner) public onlyOwner {
        _pendingOwner = newOwner;
    }

    /**
     * @dev Allows the pendingOwner address to finalize the transfer.
     */
    function claimOwnership() public onlyPendingOwner {
        emit OwnershipTransferred(_owner, _pendingOwner);
        _owner = _pendingOwner;
        _pendingOwner = address(0);
    }
}
/**
 * @title UpgradeableClaimable
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. Since
 * this contract combines Claimable and UpgradableOwnable contracts, ownership
 * can be later change via 2 step method {transferOwnership} and {claimOwnership}
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
function owner() public view returns (address) {
    return _owner;
}

/**
 * @dev Returns the address of the current owner.
 */