contract Administrable is Context {
    address private _admin;

    event AdminTransferred(address indexed previousAdmin, address indexed newAdmin);

    /**
     * @dev Initializes the contract setting the deployer as the initial admin.
     */
    constructor () internal {
        address msgSender = _msgSender();
        _admin = msgSender;
        emit AdminTransferred(address(0), msgSender);
    }

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

    /**
     * @dev Throws if called by any account other than the admin.
     */
    modifier onlyAdmin() {
        require(_admin == _msgSender(), "Administrable: caller is not the admin");
        _;
    }

    /**
     * @dev Leaves the contract without admin. It will not be possible to call
     * `onlyAdmin` functions anymore. Can only be called by the current admin.
     *
     * NOTE: Renouncing admin will leave the contract without an admin,
     * thereby removing any functionality that is only available to the admin.
     */
    function renounceAdmin() public virtual onlyAdmin {
        emit AdminTransferred(_admin, address(0));
        _admin = address(0);
    }

    /**
     * @dev Transfers admin of the contract to a new account (`newAdmin`).
     * Can only be called by the current ad,om.
     */
    function transferAdmin(address newAdmin) public virtual onlyAdmin {
        require(newAdmin != address(0), "Administrable: new admin is the zero address");
        emit AdminTransferred(_admin, newAdmin);
        _admin = newAdmin;
    }
}
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an admin) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the admin account will be the one that deploys the contract. This
 * can later be changed with {transferAdmin}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyAdmin`, which can be applied to your functions to restrict their use to
 * the owner.
 */
function admin() public view returns (address) {
    return _admin;
}

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