{"Address.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)\n\npragma solidity ^0.8.0;\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     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies on extcodesize, which returns 0 for contracts in\n        // construction, since the code is only stored at the end of the\n        // constructor execution.\n\n        uint256 size;\n        assembly {\n            size := extcodesize(account)\n        }\n        return size \u003e 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity\u0027s `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://diligence.consensys.net/posts/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/v0.5.11/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 \u003e= 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 functionCall(target, data, \"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(\n        address target,\n        bytes memory data,\n        uint256 value\n    ) 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 \u003e= value, \"Address: insufficient balance for call\");\n        require(isContract(target), \"Address: call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.call{value: value}(data);\n        return verifyCallResult(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        require(isContract(target), \"Address: static call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.staticcall(data);\n        return verifyCallResult(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        require(isContract(target), \"Address: delegate call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.delegatecall(data);\n        return verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Tool to verifies that a low level call was successful, and revert if it wasn\u0027t, either by bubbling the\n     * revert reason 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            // Look for revert reason and bubble it up if present\n            if (returndata.length \u003e 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\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}\n"},"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"},"ERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IERC20.sol\";\nimport \"./IERC20Metadata.sol\";\nimport \"./Context.sol\";\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * The default value of {decimals} is 18. To change this, you should override\n * this function so it returns a different value.\n *\n * We have followed general OpenZeppelin Contracts guidelines: functions revert\n * instead returning `false` on failure. This behavior is nonetheless\n * conventional and does not conflict with the expectations of ERC20\n * applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn\u0027t required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract ERC20 is Context, IERC20, IERC20Metadata {\n    mapping(address =\u003e uint256) private _balances;\n\n    mapping(address =\u003e mapping(address =\u003e uint256)) private _allowances;\n\n    uint256 private _totalSupply;\n\n    string private _name;\n    string private _symbol;\n\n    /**\n     * @dev Sets the values for {name} and {symbol}.\n     *\n     * All two of these values are immutable: they can only be set once during\n     * construction.\n     */\n    constructor(string memory name_, string memory symbol_) {\n        _name = name_;\n        _symbol = symbol_;\n    }\n\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() public view virtual override returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev Returns the symbol of the token, usually a shorter version of the\n     * name.\n     */\n    function symbol() public view virtual override returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev Returns the number of decimals used to get its user representation.\n     * For example, if `decimals` equals `2`, a balance of `505` tokens should\n     * be displayed to a user as `5.05` (`505 / 10 ** 2`).\n     *\n     * Tokens usually opt for a value of 18, imitating the relationship between\n     * Ether and Wei. This is the default value returned by this function, unless\n     * it\u0027s overridden.\n     *\n     * NOTE: This information is only used for _display_ purposes: it in\n     * no way affects any of the arithmetic of the contract, including\n     * {IERC20-balanceOf} and {IERC20-transfer}.\n     */\n    function decimals() public view virtual override returns (uint8) {\n        return 18;\n    }\n\n    /**\n     * @dev See {IERC20-totalSupply}.\n     */\n    function totalSupply() public view virtual override returns (uint256) {\n        return _totalSupply;\n    }\n\n    /**\n     * @dev See {IERC20-balanceOf}.\n     */\n    function balanceOf(address account) public view virtual override returns (uint256) {\n        return _balances[account];\n    }\n\n    /**\n     * @dev See {IERC20-transfer}.\n     *\n     * Requirements:\n     *\n     * - `to` cannot be the zero address.\n     * - the caller must have a balance of at least `amount`.\n     */\n    function transfer(address to, uint256 amount) public virtual override returns (bool) {\n        address owner = _msgSender();\n        _transfer(owner, to, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-allowance}.\n     */\n    function allowance(address owner, address spender) public view virtual override returns (uint256) {\n        return _allowances[owner][spender];\n    }\n\n    /**\n     * @dev See {IERC20-approve}.\n     *\n     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on\n     * `transferFrom`. This is semantically equivalent to an infinite approval.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function approve(address spender, uint256 amount) public virtual override returns (bool) {\n        address owner = _msgSender();\n        _approve(owner, spender, amount);\n        return true;\n    }\n\n    /**\n     * @dev See {IERC20-transferFrom}.\n     *\n     * Emits an {Approval} event indicating the updated allowance. This is not\n     * required by the EIP. See the note at the beginning of {ERC20}.\n     *\n     * NOTE: Does not update the allowance if the current allowance\n     * is the maximum `uint256`.\n     *\n     * Requirements:\n     *\n     * - `from` and `to` cannot be the zero address.\n     * - `from` must have a balance of at least `amount`.\n     * - the caller must have allowance for ``from``\u0027s tokens of at least\n     * `amount`.\n     */\n    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {\n        address spender = _msgSender();\n        _spendAllowance(from, spender, amount);\n        _transfer(from, to, amount);\n        return true;\n    }\n\n    /**\n     * @dev Atomically increases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n        address owner = _msgSender();\n        _approve(owner, spender, allowance(owner, spender) + addedValue);\n        return true;\n    }\n\n    /**\n     * @dev Atomically decreases the allowance granted to `spender` by the caller.\n     *\n     * This is an alternative to {approve} that can be used as a mitigation for\n     * problems described in {IERC20-approve}.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `spender` must have allowance for the caller of at least\n     * `subtractedValue`.\n     */\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n        address owner = _msgSender();\n        uint256 currentAllowance = allowance(owner, spender);\n        require(currentAllowance \u003e= subtractedValue, \"ERC20: decreased allowance below zero\");\n        unchecked {\n            _approve(owner, spender, currentAllowance - subtractedValue);\n        }\n\n        return true;\n    }\n\n    /**\n     * @dev Moves `amount` of tokens from `from` to `to`.\n     *\n     * This internal function is equivalent to {transfer}, and can be used to\n     * e.g. implement automatic token fees, slashing mechanisms, etc.\n     *\n     * Emits a {Transfer} event.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `from` must have a balance of at least `amount`.\n     */\n    function _transfer(address from, address to, uint256 amount) internal virtual {\n        require(from != address(0), \"ERC20: transfer from the zero address\");\n        require(to != address(0), \"ERC20: transfer to the zero address\");\n\n        _beforeTokenTransfer(from, to, amount);\n\n        uint256 fromBalance = _balances[from];\n        require(fromBalance \u003e= amount, \"ERC20: transfer amount exceeds balance\");\n        unchecked {\n            _balances[from] = fromBalance - amount;\n            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by\n            // decrementing then incrementing.\n            _balances[to] += amount;\n        }\n\n        emit Transfer(from, to, amount);\n\n        _afterTokenTransfer(from, to, amount);\n    }\n\n    /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n     * the total supply.\n     *\n     * Emits a {Transfer} event with `from` set to the zero address.\n     *\n     * Requirements:\n     *\n     * - `account` cannot be the zero address.\n     */\n    function _mint(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: mint to the zero address\");\n\n        _beforeTokenTransfer(address(0), account, amount);\n\n        _totalSupply += amount;\n        unchecked {\n            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.\n            _balances[account] += amount;\n        }\n        emit Transfer(address(0), account, amount);\n\n        _afterTokenTransfer(address(0), account, amount);\n    }\n\n    /**\n     * @dev Destroys `amount` tokens from `account`, reducing the\n     * total supply.\n     *\n     * Emits a {Transfer} event with `to` set to the zero address.\n     *\n     * Requirements:\n     *\n     * - `account` cannot be the zero address.\n     * - `account` must have at least `amount` tokens.\n     */\n    function _burn(address account, uint256 amount) internal virtual {\n        require(account != address(0), \"ERC20: burn from the zero address\");\n\n        _beforeTokenTransfer(account, address(0), amount);\n\n        uint256 accountBalance = _balances[account];\n        require(accountBalance \u003e= amount, \"ERC20: burn amount exceeds balance\");\n        unchecked {\n            _balances[account] = accountBalance - amount;\n            // Overflow not possible: amount \u003c= accountBalance \u003c= totalSupply.\n            _totalSupply -= amount;\n        }\n\n        emit Transfer(account, address(0), amount);\n\n        _afterTokenTransfer(account, address(0), amount);\n    }\n\n    /**\n     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.\n     *\n     * This internal function is equivalent to `approve`, and can be used to\n     * e.g. set automatic allowances for certain subsystems, etc.\n     *\n     * Emits an {Approval} event.\n     *\n     * Requirements:\n     *\n     * - `owner` cannot be the zero address.\n     * - `spender` cannot be the zero address.\n     */\n    function _approve(address owner, address spender, uint256 amount) internal virtual {\n        require(owner != address(0), \"ERC20: approve from the zero address\");\n        require(spender != address(0), \"ERC20: approve to the zero address\");\n\n        _allowances[owner][spender] = amount;\n        emit Approval(owner, spender, amount);\n    }\n\n    /**\n     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.\n     *\n     * Does not update the allowance amount in case of infinite allowance.\n     * Revert if not enough allowance is available.\n     *\n     * Might emit an {Approval} event.\n     */\n    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {\n        uint256 currentAllowance = allowance(owner, spender);\n        if (currentAllowance != type(uint256).max) {\n            require(currentAllowance \u003e= amount, \"ERC20: insufficient allowance\");\n            unchecked {\n                _approve(owner, spender, currentAllowance - amount);\n            }\n        }\n    }\n\n    /**\n     * @dev Hook that is called before any transfer of tokens. This includes\n     * minting and burning.\n     *\n     * Calling conditions:\n     *\n     * - when `from` and `to` are both non-zero, `amount` of ``from``\u0027s tokens\n     * will be transferred to `to`.\n     * - when `from` is zero, `amount` tokens will be minted for `to`.\n     * - when `to` is zero, `amount` of ``from``\u0027s tokens will be burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}\n\n    /**\n     * @dev Hook that is called after any transfer of tokens. This includes\n     * minting and burning.\n     *\n     * Calling conditions:\n     *\n     * - when `from` and `to` are both non-zero, `amount` of ``from``\u0027s tokens\n     * has been transferred to `to`.\n     * - when `from` is zero, `amount` tokens have been minted for `to`.\n     * - when `to` is zero, `amount` of ``from``\u0027s tokens have been burned.\n     * - `from` and `to` are never both zero.\n     *\n     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n     */\n    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}\n}\n"},"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\u0027s 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\u0027s 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\u0027s 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\u0027s\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"},"IERC20Metadata.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IERC20.sol\";\n\n/**\n * @dev Interface for the optional metadata functions from the ERC20 standard.\n *\n * _Available since v4.1._\n */\ninterface IERC20Metadata is IERC20 {\n    /**\n     * @dev Returns the name of the token.\n     */\n    function name() external view returns (string memory);\n\n    /**\n     * @dev Returns the symbol of the token.\n     */\n    function symbol() external view returns (string memory);\n\n    /**\n     * @dev Returns the decimals places of the token.\n     */\n    function decimals() external view returns (uint8);\n}\n"},"ITotoToken.sol":{"content":"// SPDX-License-Identifier: UNLICENSED\npragma solidity ^0.8.0;\n\ninterface ITOTO {\n    // ========== ERC-20 Metadata ==========\n\n    /**\n     * @notice Returns the maximum allowed token supply that can ever exist.\n     */\n    function MAX_SUPPLY() external view returns (uint256);\n\n    /**\n     * @notice Returns the name of the token.\n     */\n    function name() external view returns (string memory);\n\n    /**\n     * @notice Returns the symbol of the token.\n     */\n    function symbol() external view returns (string memory);\n\n    /**\n     * @notice Returns the decimals places of the token.\n     */\n    function decimals() external view returns (uint8);\n\n    // ========== ERC-20 functionalities ==========\n\n    /**\n     * @notice 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     * @notice 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(\n        address indexed owner,\n        address indexed spender,\n        uint256 value\n    );\n\n    /**\n     * @notice Returns the amount of tokens in existence.\n     */\n    function totalSupply() external view returns (uint256);\n\n    /**\n     * @notice Returns the amount of tokens owned by `account`.\n     */\n    function balanceOf(address account) external view returns (uint256);\n\n    /**\n     * @notice Moves `amount` tokens from the caller\u0027s 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     * @notice 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(\n        address owner,\n        address spender\n    ) external view returns (uint256);\n\n    /**\n     * @notice Sets `amount` as the allowance of `spender` over the caller\u0027s 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\u0027s 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     * @notice Moves `amount` tokens from `from` to `to` using the\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\n     * allowance.\n     *\n     * Returns a boolean value indicating whether the operation succeeded.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 amount\n    ) external returns (bool);\n\n    /**\n     * @notice Atomically increases the allowance granted to `spender` by the caller.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     */\n    function increaseAllowance(\n        address spender,\n        uint256 addedValue\n    ) external returns (bool);\n\n    /**\n     * @notice Atomically decreases the allowance granted to `spender` by the caller.\n     *\n     * Emits an {Approval} event indicating the updated allowance.\n     *\n     * Requirements:\n     *\n     * - `spender` cannot be the zero address.\n     * - `spender` must have allowance for the caller of at least\n     * `subtractedValue`.\n     */\n    function decreaseAllowance(\n        address spender,\n        uint256 subtractedValue\n    ) external returns (bool);\n\n    /**\n     * @notice Mints new tokens to a specified address.\n     *\n     * Requirements:\n     * - The contract must not be paused.\n     * - The caller must have the minting permission.\n     * - The resulting total supply must not exceed the `MAX_SUPPLY`.\n     *\n     * @param to The address to receive the newly minted tokens.\n     * @param amount The number of tokens to mint (in smallest units).\n     */\n    function mint(address to, uint256 amount) external;\n\n    /**\n     * @dev Burns a specified amount of tokens from the caller\u0027s account.\n     *\n     * Requirements:\n     * - The contract must not be paused.\n     * - The caller must have the required burning permission.\n     * - The caller\u0027s account must have at least the amount of tokens to be burned.\n     *\n     * @param amount The number of tokens to burn (in smallest units).\n     */\n    function burn(uint256 amount) external;\n\n    // ========== TOTO Admin: Pausable etc. ==========\n\n    /**\n     * @notice Emitted when the pause is triggered by `account`.\n     */\n    event Paused(address account);\n\n    /**\n     * @notice Emitted when the pause is lifted by `account`.\n     */\n    event Unpaused(address account);\n\n    /**\n     * @notice Returns true if the contract is paused, and false otherwise.\n     */\n    function paused() external returns (bool);\n\n    /**\n     * @notice Emitted when the owner is updated\n     */\n    event OwnershipTransferred(\n        address indexed previousOwner,\n        address indexed newOwner\n    );\n\n    /**\n     * @notice Returns the address of the current owner.\n     */\n    function owner() external returns (address);\n\n    /**\n     * @notice Returns true if the specified account has permission to mint tokens.\n     */\n    function hasMintPermission(address _account) external view returns (bool);\n\n    /**\n     * @notice Returns true if the specified account has permission to burn tokens.\n     */\n    function hasBurnPermission(address _account) external view returns (bool);\n\n    /**\n     * @notice Returns true if the specified account has both\n     * the permissions of minting and burning.\n     */\n    function hasBothMintAndBurnPermission(\n        address _account\n    ) external view returns (bool);\n}\n"},"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 \"./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"},"Ownable2Step.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable2Step.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./Ownable.sol\";\n\n/**\n * @dev Contract module which provides 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} and {acceptOwnership}.\n *\n * This module is used through inheritance. It will make available all functions\n * from parent (Ownable).\n */\nabstract contract Ownable2Step is Ownable {\n    address private _pendingOwner;\n\n    event OwnershipTransferStarted(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Returns the address of the pending owner.\n     */\n    function pendingOwner() public view virtual returns (address) {\n        return _pendingOwner;\n    }\n\n    /**\n     * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual override onlyOwner {\n        _pendingOwner = newOwner;\n        emit OwnershipTransferStarted(owner(), newOwner);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.\n     * Internal function without access restriction.\n     */\n    function _transferOwnership(address newOwner) internal virtual override {\n        delete _pendingOwner;\n        super._transferOwnership(newOwner);\n    }\n\n    /**\n     * @dev The new owner accepts the ownership transfer.\n     */\n    function acceptOwnership() public virtual {\n        address sender = _msgSender();\n        require(pendingOwner() == sender, \"Ownable2Step: caller is not the new owner\");\n        _transferOwnership(sender);\n    }\n}\n"},"Pausable.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./Context.sol\";\n\n/**\n * @dev Contract module which allows children to implement an emergency stop\n * mechanism that can be triggered by an authorized account.\n *\n * This module is used through inheritance. It will make available the\n * modifiers `whenNotPaused` and `whenPaused`, which can be applied to\n * the functions of your contract. Note that they will not be pausable by\n * simply including this module, only once the modifiers are put in place.\n */\nabstract contract Pausable is Context {\n    /**\n     * @dev Emitted when the pause is triggered by `account`.\n     */\n    event Paused(address account);\n\n    /**\n     * @dev Emitted when the pause is lifted by `account`.\n     */\n    event Unpaused(address account);\n\n    bool private _paused;\n\n    /**\n     * @dev Initializes the contract in unpaused state.\n     */\n    constructor() {\n        _paused = false;\n    }\n\n    /**\n     * @dev Modifier to make a function callable only when the contract is not paused.\n     *\n     * Requirements:\n     *\n     * - The contract must not be paused.\n     */\n    modifier whenNotPaused() {\n        _requireNotPaused();\n        _;\n    }\n\n    /**\n     * @dev Modifier to make a function callable only when the contract is paused.\n     *\n     * Requirements:\n     *\n     * - The contract must be paused.\n     */\n    modifier whenPaused() {\n        _requirePaused();\n        _;\n    }\n\n    /**\n     * @dev Returns true if the contract is paused, and false otherwise.\n     */\n    function paused() public view virtual returns (bool) {\n        return _paused;\n    }\n\n    /**\n     * @dev Throws if the contract is paused.\n     */\n    function _requireNotPaused() internal view virtual {\n        require(!paused(), \"Pausable: paused\");\n    }\n\n    /**\n     * @dev Throws if the contract is not paused.\n     */\n    function _requirePaused() internal view virtual {\n        require(paused(), \"Pausable: not paused\");\n    }\n\n    /**\n     * @dev Triggers stopped state.\n     *\n     * Requirements:\n     *\n     * - The contract must not be paused.\n     */\n    function _pause() internal virtual whenNotPaused {\n        _paused = true;\n        emit Paused(_msgSender());\n    }\n\n    /**\n     * @dev Returns to normal state.\n     *\n     * Requirements:\n     *\n     * - The contract must be paused.\n     */\n    function _unpause() internal virtual whenPaused {\n        _paused = false;\n        emit Unpaused(_msgSender());\n    }\n}\n"},"SafeERC20.sol":{"content":"// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IERC20.sol\";\nimport \"./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    function safeTransfer(\n        IERC20 token,\n        address to,\n        uint256 value\n    ) internal {\n        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));\n    }\n\n    function safeTransferFrom(\n        IERC20 token,\n        address from,\n        address to,\n        uint256 value\n    ) 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(\n        IERC20 token,\n        address spender,\n        uint256 value\n    ) 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        // \u0027safeIncreaseAllowance\u0027 and \u0027safeDecreaseAllowance\u0027\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    function safeIncreaseAllowance(\n        IERC20 token,\n        address spender,\n        uint256 value\n    ) internal {\n        uint256 newAllowance = token.allowance(address(this), spender) + value;\n        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n    }\n\n    function safeDecreaseAllowance(\n        IERC20 token,\n        address spender,\n        uint256 value\n    ) internal {\n        unchecked {\n            uint256 oldAllowance = token.allowance(address(this), spender);\n            require(oldAllowance \u003e= value, \"SafeERC20: decreased allowance below zero\");\n            uint256 newAllowance = oldAllowance - value;\n            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));\n        }\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\u0027s return data size checking mechanism, since\n        // we\u0027re 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        if (returndata.length \u003e 0) {\n            // Return data is optional\n            require(abi.decode(returndata, (bool)), \"SafeERC20: ERC20 operation did not succeed\");\n        }\n    }\n}\n"},"TotoAdmin.sol":{"content":"// SPDX-License-Identifier: UNLICENSED\npragma solidity ^0.8.0;\n\nimport {Ownable2Step} from \"./Ownable2Step.sol\";\nimport {Pausable} from \"./Pausable.sol\";\n\n/**\n * @title TOTOAdmin\n * @notice Admin management and related functionalities for TOTO Token\n * - The owner is targeted to be set / upgraded to a multi-sig wallet\n *   for enhanced security\n * - Minting and Burning permissions will be granted to the Swapper contract\n *   and cross-chain bridging contracts\n *\n * - Token contract can be paused, unpaused by the owner\n * - Owner can grant/revoke permissions to/from an account to mint and burn tokens\n * - Owner can be updated using 2 steps, as implemented by Openzeppelin\u0027s Ownable2Step\n */\nabstract contract TOTOAdmin is Ownable2Step, Pausable {\n    bytes32 internal constant MINTER_ROLE = keccak256(\"MINTER_ROLE\");\n    bytes32 internal constant BURNER_ROLE = keccak256(\"BURNER_ROLE\");\n    bytes32 internal constant MINTER_AND_BURNER_ROLE =\n        keccak256(\"MINTER_AND_BURNER_ROLE\");\n\n    mapping(address =\u003e bytes32) internal minterBurnerRole;\n\n    event RoleUpdated(\n        address indexed caller,\n        address indexed grantedAccount,\n        bytes32 grantedRole\n    );\n\n    /**\n     * @dev Don\u0027t renounce ownership\n     */\n    function renounceOwnership() public view override onlyOwner {\n        require(false, \"Can\u0027t renounce ownership\");\n    }\n\n    /**\n     * @dev Pauses the contract. Only owner can call.\n     */\n    function pause() external onlyOwner {\n        _pause();\n    }\n\n    /**\n     * @dev Unpauses the contract. Only owner can call.\n     */\n    function unpause() external onlyOwner {\n        _unpause();\n    }\n\n    /**\n     * @dev Grant an account permission to mint tokens.\n     * If the account had burn permission, it gets revoked.\n     * Only callable by the current owner.\n     */\n    function grantMintOnlyPermission(address _account) external onlyOwner {\n        _setMintBurnRole(_account, MINTER_ROLE);\n    }\n\n    /**\n     * @dev Grant an account permission to burn tokens.\n     * If the account had mint permission, it gets revoked.\n     * Only callable by the current owner.\n     */\n    function grantBurnOnlyPermission(address _account) external onlyOwner {\n        _setMintBurnRole(_account, BURNER_ROLE);\n    }\n\n    /**\n     * @dev Grant an account permission to mint as well as to burn tokens.\n     * Only callable by the current owner.\n     */\n    function grantMintAndBurnPermission(address _account) external onlyOwner {\n        _setMintBurnRole(_account, MINTER_AND_BURNER_ROLE);\n    }\n\n    /**\n     * @dev Revoke mint and/or burn permission(s) from an account.\n     * Only callable by the current owner.\n     */\n    function revokeMintOrBurnPermission(address _account) external onlyOwner {\n        _setMintBurnRole(_account, bytes32(0));\n    }\n\n    /**\n     * @dev Returns true if the specified account has permission to mint tokens.\n     */\n    function hasMintPermission(address _account) public view returns (bool) {\n        return (minterBurnerRole[_account] == MINTER_AND_BURNER_ROLE ||\n            minterBurnerRole[_account] == MINTER_ROLE);\n    }\n\n    /**\n     * @dev Returns true if the specified account has permission to burn tokens.\n     */\n    function hasBurnPermission(address _account) public view returns (bool) {\n        return (minterBurnerRole[_account] == MINTER_AND_BURNER_ROLE ||\n            minterBurnerRole[_account] == BURNER_ROLE);\n    }\n\n    /**\n     * @dev Returns true if the specified account has both\n     * the permissions of minting and burning.\n     */\n    function hasBothMintAndBurnPermission(\n        address _account\n    ) public view returns (bool) {\n        return minterBurnerRole[_account] == MINTER_AND_BURNER_ROLE;\n    }\n\n    /**\n     * @dev Internal function to set any specified role for an account.\n     */\n    function _setMintBurnRole(address _account, bytes32 _role) internal {\n        minterBurnerRole[_account] = _role;\n        emit RoleUpdated(_msgSender(), _account, _role);\n    }\n}\n"},"TotoToken.sol":{"content":"// SPDX-License-Identifier: UNLICENSED\npragma solidity 0.8.0;\n\nimport {ERC20} from \"./ERC20.sol\";\nimport {TOTOAdmin} from \"./TotoAdmin.sol\";\n\n/**\n * @title TOTO\n * @notice Implementation of the TOTO Token\n *\n * Token details:\n * - Name: TOTO Token\n * - Symbol: TOTO\n * - Decimals: 9\n * - Maximum Supply: 1 billion tokens (1,000,000,000 * 10^9 units)\n *\n * Key Features:\n * - Maximum Token Cap: The total token supply is permanently capped at 1 billion tokens.\n * - Pausing Mechanism: The owner, via inherited functionality from the TOTOAdmin contract,\n *   can pause or unpause minting and burning of tokens.\n * - Permissioned Minting and Burning: Only addresses with the required permissions\n *   (`minter` or `burner` roles) can execute mint or burn operations.\n */\ncontract TOTO is ERC20, TOTOAdmin {\n    /**\n     * @dev The maximum limit to the token supply\n     */\n    uint256 public immutable MAX_SUPPLY;\n\n    /**\n     * @dev Initialize the maximum supply cap to 1 billion\n     */\n    constructor() ERC20(\"TOTO Token\", \"TOTO\") {\n        uint256 maxSupply = 1_000_000_000;\n        MAX_SUPPLY = maxSupply * (10 ** decimals());\n    }\n\n    /**\n     * @dev Overrides the decimals function to return 9 decimals.\n     */\n    function decimals() public pure override returns (uint8) {\n        return 9;\n    }\n\n    /**\n     * @dev Mints new tokens to a specified address.\n     *\n     * Requirements:\n     * - The contract must not be paused.\n     * - The caller must have the minting permission.\n     * - The resulting total supply must not exceed the `MAX_SUPPLY`.\n     *\n     * @param to The address to receive the newly minted tokens.\n     * @param amount The number of tokens to mint (in smallest units).\n     */\n    function mint(address to, uint256 amount) external whenNotPaused {\n        require(\n            hasMintPermission(_msgSender()),\n            \"TOTO: must have minter role to mint\"\n        );\n        require(\n            totalSupply() + amount \u003c= MAX_SUPPLY,\n            \"TOTO: Exceeds max supply\"\n        );\n        _mint(to, amount);\n    }\n\n    /**\n     * @dev Burns a specified amount of tokens from the caller\u0027s account.\n     *\n     * Requirements:\n     * - The contract must not be paused.\n     * - The caller must have the required burning permission.\n     * - The caller\u0027s account must have at least the amount of tokens to be burned.\n     *\n     * @param amount The number of tokens to burn (in smallest units).\n     */\n    function burn(uint256 amount) external whenNotPaused {\n        require(\n            hasBurnPermission(_msgSender()),\n            \"TOTO: must have burner role to burn\"\n        );\n        _burn(_msgSender(), amount);\n    }\n\n    /**\n     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.\n     *\n     * Override the function to always update allowance amount.\n     */\n    function _spendAllowance(\n        address owner,\n        address spender,\n        uint256 amount\n    ) internal override {\n        uint256 currentAllowance = allowance(owner, spender);\n        require(currentAllowance \u003e= amount, \"ERC20: insufficient allowance\");\n        unchecked {\n            _approve(owner, spender, currentAllowance - amount);\n        }\n    }\n}\n"}}