Contract Address Details

/**
 *Submitted for verification at Etherscan.io on 2021-08-31
*/

// Sources flattened with hardhat v2.3.3 https://hardhat.org

// File @openzeppelin/contracts/utils/Context.sol@v3.4.1

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.9;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}


// File @openzeppelin/contracts/token/ERC20/IERC20.sol@v3.4.1
pragma solidity ^0.8.9;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}


// File @openzeppelin/contracts/math/SafeMath.sol@v3.4.1

pragma solidity ^0.8.9;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}


// File @openzeppelin/contracts/token/ERC20/ERC20.sol@v3.4.1

pragma solidity ^0.8.9;



/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _decimals = 18;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal virtual {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}


// File @openzeppelin/contracts/introspection/IERC165.sol@v3.4.1

pragma solidity ^0.8.9;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}


// File @eth-optimism/contracts/libraries/standards/IL2StandardERC20.sol@v0.4.6

pragma solidity ^0.8.9;


interface IL2StandardERC20 is IERC20, IERC165 {
    function l1Token() external returns (address);

    function mint(address _to, uint256 _amount) external;

    function burn(address _from, uint256 _amount) external;

    event Mint(address indexed _account, uint256 _amount);
    event Burn(address indexed _account, uint256 _amount);
}


// File @eth-optimism/contracts/libraries/standards/L2StandardERC20.sol@v0.4.6

pragma solidity ^0.8.9;

contract L2StandardERC20 is IL2StandardERC20, ERC20 {
    address public override l1Token;
    address public l2Bridge;

    /**
     * @param _l2Bridge Address of the L2 standard bridge.
     * @param _l1Token Address of the corresponding L1 token.
     * @param _name ERC20 name.
     * @param _symbol ERC20 symbol.
     */
    constructor(
        address _l2Bridge,
        address _l1Token,
        string memory _name,
        string memory _symbol
    )
        ERC20(_name, _symbol) {
        l1Token = _l1Token;
        l2Bridge = _l2Bridge;
    }

    modifier onlyL2Bridge {
        require(msg.sender == l2Bridge, "Only L2 Bridge can mint and burn");
        _;
    }

    function supportsInterface(bytes4 _interfaceId) public override pure returns (bool) {
        bytes4 firstSupportedInterface = bytes4(keccak256("supportsInterface(bytes4)")); // ERC165
        bytes4 secondSupportedInterface = IL2StandardERC20.l1Token.selector
            ^ IL2StandardERC20.mint.selector
            ^ IL2StandardERC20.burn.selector;
        return _interfaceId == firstSupportedInterface || _interfaceId == secondSupportedInterface;
    }

    function mint(address _to, uint256 _amount) public virtual override onlyL2Bridge {
        _mint(_to, _amount);

        emit Mint(_to, _amount);
    }

    function burn(address _from, uint256 _amount) public virtual override onlyL2Bridge {
        _burn(_from, _amount);

        emit Burn(_from, _amount);
    }
}


// File contracts/USDC/lib/Ownable.sol

// Copyright (c) 2021 Coinbase, Inc.

pragma solidity ^0.8.9;

/**
 * @notice Ownable
 * @dev Similar to OpenZeppelin's Ownable.
 * Differences:
 * - An internally callable _changeOwner() function
 * - No renounceOwnership() function
 * - No constructor
 * - No GSN support
 */
abstract contract Ownable {
    address internal _owner;

    /**
     * @notice Emitted when the owner changes.
     * @param previousOwner Previous owner's address
     * @param newOwner New owner's address
     */
    event OwnerChanged(address indexed previousOwner, address indexed newOwner);

    /**
     * @notice Throw if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == msg.sender, "caller is not the owner");
        _;
    }

    /**
     * @notice Return the address of the current owner.
     * @return Owner's address
     */
    function owner() external view returns (address) {
        return _owner;
    }

    /**
     * @notice Change the owner. Can only be called by the current owner.
     * @param account New owner's address
     */
    function changeOwner(address account) external onlyOwner {
        _changeOwner(account);
    }

    /**
     * @notice Internal function to change the owner.
     * @param account New owner's address
     */
    function _changeOwner(address account) internal {
        require(account != address(0), "account is the zero address");
        require(account != address(this), "account is this contract");
        emit OwnerChanged(_owner, account);
        _owner = account;
    }
}


// File contracts/USDC/lib/Pausable.sol

// Copyright (c) 2021 Coinbase, Inc.

pragma solidity ^0.8.9;

/**
 * @notice Pausable
 * @dev Similar to OpenZeppelin's Pausable.
 * Differences:
 * - Has the pauser role
 * - External pause/unpause functions callable by the pauser
 * - No constructor
 * - No GSN support
 */
abstract contract Pausable is Ownable {
    address private _pauser;
    bool private _paused;

    /**
     * @notice Emitted when the pauser changes.
     * @param previousPauser Previous pauser's address
     * @param newPauser New pauser's address
     */
    event PauserChanged(
        address indexed previousPauser,
        address indexed newPauser
    );

    /**
     * @notice Emitted when the contract is paused.
     * @param pauser Pauser's address
     */
    event Paused(address pauser);

    /**
     * @notice Emitted when the contract is unpaused.
     * @param pauser Pauser's address
     */
    event Unpaused(address pauser);

    /**
     * @notice Callable only by the pauser.
     */
    modifier onlyPauser() {
        require(msg.sender == _pauser, "caller is not the pauser");
        _;
    }

    /**
     * @notice Callable only when the contract is not paused.
     */
    modifier whenNotPaused() {
        require(!_paused, "contract is paused");
        _;
    }

    /**
     * @notice Callable only when the contract is paused.
     */
    modifier whenPaused() {
        require(_paused, "contract is not paused");
        _;
    }

    /**
     * @notice Return the current pauser.
     * @return Pauser's address
     */
    function pauser() external view returns (address) {
        return _pauser;
    }

    /**
     * @notice Return whether the contract is paused.
     * @return True if paused
     */
    function paused() external view returns (bool) {
        return _paused;
    }

    /**
     * @notice Pause the contract.
     */
    function pause() external onlyPauser {
        _paused = true;
        emit Paused(msg.sender);
    }

    /**
     * @notice Unpause the contract.
     */
    function unpause() external onlyPauser {
        _paused = false;
        emit Unpaused(msg.sender);
    }

    /**
     * @notice Set a new pauser.
     * @param account New pauser's address
     */
    function setPauser(address account) external onlyOwner {
        _setPauser(account);
    }

    /**
     * @notice Initial function to set the pauser.
     * @param account New pauser's address
     */
    function _setPauser(address account) internal {
        emit PauserChanged(_pauser, account);
        _pauser = account;
    }
}


// File contracts/USDC/lib/Blacklistable.sol

/**
 *
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity ^0.8.9;

abstract contract Blacklistable is Ownable {
    address internal _blacklister;
    mapping(address => bool) internal _blacklisted;

    event Blacklisted(address indexed account);
    event UnBlacklisted(address indexed account);
    event BlacklisterChanged(address indexed newBlacklister);

    /**
     * @notice Throw if called by any account other than the blacklister
     */
    modifier onlyBlacklister() {
        require(msg.sender == _blacklister, "caller is not the blacklister");
        _;
    }

    /**
     * @notice Throw if argument account is blacklisted
     * @param account The address to check
     */
    modifier notBlacklisted(address account) {
        require(!_blacklisted[account], "account is blacklisted");
        _;
    }

    /**
     * @notice Blacklister address
     * @return Address
     */
    function blacklister() external view returns (address) {
        return _blacklister;
    }

    /**
     * @notice Check whether a given account is blacklisted
     * @param account The address to check
     */
    function isBlacklisted(address account) external view returns (bool) {
        return _blacklisted[account];
    }

    /**
     * @notice Add an account to blacklist
     * @param account The address to blacklist
     */
    function blacklist(address account) external onlyBlacklister {
        _blacklisted[account] = true;
        emit Blacklisted(account);
    }

    /**
     * @notice Remove an account from blacklist
     * @param account The address to remove from the blacklist
     */
    function unBlacklist(address account) external onlyBlacklister {
        _blacklisted[account] = false;
        emit UnBlacklisted(account);
    }

    /**
     * @notice Change the blacklister
     * @param newBlacklister new blacklister's address
     */
    function updateBlacklister(address newBlacklister) external onlyOwner {
        require(
            newBlacklister != address(0),
            "new blacklister is the zero address"
        );
        _blacklister = newBlacklister;
        emit BlacklisterChanged(_blacklister);
    }
}


// File contracts/USDC/OVMFiatToken.sol

// Copyright (c) 2021 Coinbase, Inc.

pragma solidity ^0.8.9;





contract OVMFiatToken is L2StandardERC20, Ownable, Pausable, Blacklistable {
    constructor(
        address _l2Bridge,
        address _l1Token,
        address owner,
        string memory name,
        string memory symbol,
        uint8 decimals
    ) L2StandardERC20(_l2Bridge, _l1Token, name, symbol) {
        _setupDecimals(decimals);
        _changeOwner(owner);
    }

    function mint(address account, uint256 amount)
        public
        override
        whenNotPaused
        notBlacklisted(account)
        onlyL2Bridge
    {
        super.mint(account, amount);
    }

    function burn(address account, uint256 amount)
        public
        override
        whenNotPaused
        notBlacklisted(account)
        onlyL2Bridge
    {
        super.burn(account, amount);
    }

    function approve(address spender, uint256 amount)
        public
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        return super.approve(spender, amount);
    }

    function increaseAllowance(address spender, uint256 addedValue)
        public
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        return super.increaseAllowance(spender, addedValue);
    }

    function decreaseAllowance(address spender, uint256 subtractedValue)
        public
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        return super.decreaseAllowance(spender, subtractedValue);
    }

    function transfer(address recipient, uint256 amount)
        public
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(recipient)
        returns (bool)
    {
        return super.transfer(recipient, amount);
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    )
        public
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(sender)
        notBlacklisted(recipient)
        returns (bool)
    {
        return super.transferFrom(sender, recipient, amount);
    }
}