// File: OpiPets/R33lzPresale.sol



/**
    Presale contract for R33LZ Token with CA: 0x5D3957DF518adE9AdfD7c4341a0cf7D6D73EC682
    Author: Arrnaya (TG: @arrnaya)
*/

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

import "./Ownable.sol";
import "./Address.sol";
import "./IERC20.sol";
import "./Context.sol";
import "./ReentrancyGuard.sol";
import "./ETHPriceFeeds.sol";

contract R33lzPresale is Ownable, ReentrancyGuard, PriceConsumerV3 {
    using Address for address payable;

    event Swap(
        address indexed user,
        uint256 inAmount,
        uint256 owedToInvestorAmount
    );
    event Claimed(address indexed user, uint256 amount);
    event PayeeTransferred(
        address indexed previousPayee,
        address indexed newPayee
    );
    event ETHCollected(address user, uint256 amount);
    event IERC20TokenWithdrawn(address user, uint256 amount);
    event USDTWithdrawn(address user, uint256 amount);

    IERC20 public r33lzToken;
    IERC20 public USDT;
    uint256 public ETHPriceInUSD;
    address public fundCollectorWallet;

    bool public isSwapStarted;
    bool public isVested;
    bool public canClaim;

    uint256 public swapRate = 1818; // 1818 R33LZ Tokens per USDT
    uint256 public totalTokensSold;
    uint256 public maxTokensToSell = 90_000_000 * 1e18; // Max 90M R33LZ tokens to be sold

    uint256 public totalFundsRaised;
    uint256 public minBuyPerWallet = 100 * 1e18; // $100
    uint256 public maxBuyPerWallet = 1000 * 1e18; // $1000

    uint256 public daysPerVest;
    uint256 public percentPerVest;
    uint256 public initialClaimPercentage;
    uint256 public vestingStartDate;

    mapping(address => uint256) public spentByInvestor;
    mapping(address => uint256) public owedToInvestor;
    mapping(address => uint256) public claimedByInvestor;

    constructor(
        address _paymentCollectionWallet,
        IERC20 _r33lzToken,
        IERC20 _USDT,
        bool _vestingStatus
    ) {
        require(
            address(_r33lzToken) != address(0) &&
                _paymentCollectionWallet != address(0) &&
                address(_USDT) != address(0),
            "r33lzPresale: Can't set token to zero address"
        );

        // setVestingParameters (_daysPerVest, _percentPerVest, _initialClaimPercentage);
        r33lzToken = _r33lzToken;
        USDT = _USDT;
        fundCollectorWallet = _paymentCollectionWallet;
        isVested = _vestingStatus;
    }

    // Function to receive Ether. msg.data must be empty
    receive() external payable {}

    function _swap() external payable nonReentrant {
        getETHPrice();

        uint256 investmentAmnt = (msg.value * ETHPriceInUSD) / 1e8;

        require(isSwapStarted == true, "r33lzPresale: Swap not started");
        require(
            totalTokensSold + (investmentAmnt * swapRate) <= maxTokensToSell,
            "r33lzPresale: Exceeding total fund raise limit"
        );
        require(
            spentByInvestor[msg.sender] + investmentAmnt <= maxBuyPerWallet &&
                spentByInvestor[msg.sender] + investmentAmnt >= minBuyPerWallet,
            "r33lzPresale: Try an amount above min but below max allowed per wallet!"
        );

        uint256 quota = r33lzToken.balanceOf(address(this));
        uint256 outAmount = investmentAmnt * swapRate;
        require(
            totalTokensSold + outAmount <= quota,
            "r33lzPresale: Not enough tokens remaining"
        );

        totalTokensSold += outAmount;
        totalFundsRaised += investmentAmnt;
        payable(address(this)).sendValue(msg.value);
        spentByInvestor[msg.sender] += investmentAmnt;
        owedToInvestor[msg.sender] += outAmount;

        emit Swap(msg.sender, investmentAmnt, outAmount);
    }

    function _swapWithUSDT(uint256 weiAmount) external nonReentrant {
        require(isSwapStarted == true, "r33lzPresale: Swap not started");
        require(
            totalTokensSold + (weiAmount * swapRate) <= maxTokensToSell,
            "r33lzPresale: Exceeding total fund raise limit"
        );
        require(
            spentByInvestor[msg.sender] + weiAmount <= maxBuyPerWallet &&
                spentByInvestor[msg.sender] + weiAmount >= minBuyPerWallet,
            "r33lzPresale: Try an amount above min but below max allowed per wallet!"
        );

        uint256 quota = r33lzToken.balanceOf(address(this));
        uint256 outAmount = weiAmount * swapRate;
        require(
            totalTokensSold + outAmount <= quota,
            "r33lzPresale: Not enough tokens remaining"
        );

        totalTokensSold += outAmount;
        totalFundsRaised += weiAmount;
        IERC20(USDT).transferFrom(msg.sender, address(this), weiAmount);
        spentByInvestor[msg.sender] += weiAmount;
        owedToInvestor[msg.sender] += outAmount;

        emit Swap(msg.sender, weiAmount, outAmount);
    }

    function getETHPrice() internal returns (int256) {
        (
            ,
            /* uint80 roundID */
            int256 price, /*uint startedAt*/ /*uint timeStamp*/ /*uint80 answeredInRound*/
            ,
            ,

        ) = priceFeed.latestRoundData();
        ETHPriceInUSD = uint256(price);

        return price;
    }

    function claim() external nonReentrant {
        require(canClaim == true, "r33lzPresale: Can't claim yet");

        uint256 quota = r33lzToken.balanceOf(address(this));

        if (isVested) {
            uint256 numberOfVests = (block.timestamp - vestingStartDate) /
                daysPerVest; // rounds down
            uint256 owedToInvestorNow = (owedToInvestor[msg.sender] *
                initialClaimPercentage) /
                100 +
                (owedToInvestor[msg.sender] * numberOfVests * percentPerVest) /
                100;

            if (owedToInvestorNow > owedToInvestor[msg.sender])
                owedToInvestorNow = owedToInvestor[msg.sender];

            require(
                owedToInvestorNow - claimedByInvestor[msg.sender] <= quota,
                "r33lzPresale: Not enough tokens remaining"
            );
            require(
                owedToInvestorNow - claimedByInvestor[msg.sender] > 0,
                "r33lzPresale: No tokens left to claim"
            );

            uint256 amount = owedToInvestorNow - claimedByInvestor[msg.sender];
            claimedByInvestor[msg.sender] += owedToInvestorNow;
            r33lzToken.transfer(msg.sender, amount);

            emit Claimed(msg.sender, amount);
        } else {
            uint256 owedToInvestorNow = owedToInvestor[msg.sender];
            require(
                owedToInvestorNow - claimedByInvestor[msg.sender] <= quota,
                "r33lzPresale: Not enough tokens remaining"
            );
            require(
                owedToInvestorNow - claimedByInvestor[msg.sender] > 0,
                "r33lzPresale: No tokens left to claim"
            );

            uint256 amount = owedToInvestorNow;
            claimedByInvestor[msg.sender] += owedToInvestorNow;
            r33lzToken.transfer(msg.sender, amount);

            emit Claimed(msg.sender, amount);
        }
    }

    function setVestingParameters(
        uint256 _daysPerVest,
        uint256 _percentPerVest,
        uint256 _initialClaimPercentage
    ) external onlyOwner {
        require(isVested, "This is not a vested presale!");
        require(
            _initialClaimPercentage <= 100,
            "r33lzPresale: Initial claim % must be <= 100"
        );
        require(
            _percentPerVest <= 100,
            "r33lzPresale: % per vest must be <= 100"
        );

        daysPerVest = _daysPerVest * 1 days;
        percentPerVest = _percentPerVest;
        initialClaimPercentage = _initialClaimPercentage;
    }

    function setVestingStartDate(uint256 _vestingStartDate) external onlyOwner {
        require(isVested, "This is not a vested presale!");
        require(
            _vestingStartDate > block.timestamp,
            "r33lzPresale: Vesting must start in the future"
        );

        vestingStartDate = _vestingStartDate;
    }

    function toggleSwap(bool enableSwap) external onlyOwner {
        isSwapStarted = enableSwap;
    }

    function setClaim(bool _canClaim) external onlyOwner {
        canClaim = _canClaim;

        if (_canClaim && isVested && vestingStartDate == 0)
            vestingStartDate = block.timestamp;
    }

    function _changeLimits(uint256 _newMinBuy, uint256 _newMaxBuy) external onlyOwner {
        require(_newMinBuy > 0 && _newMaxBuy > 0, "Can't set 0 value");
        minBuyPerWallet = _newMinBuy * 1e18;
        maxBuyPerWallet = _newMaxBuy * 1e18;
    }

    function _updateSwapRate(uint256 _newRate) external onlyOwner {
        require(_newRate > 0, "Can't set 0 value");
        swapRate = _newRate;
    }

    function _changeFundCollectorWalletAddress(address newPayee)
        external
        onlyOwner
    {
        require(
            newPayee != address(0),
            "r33lzPresale: Can't set payee to zero address"
        );
        fundCollectorWallet = newPayee;

        emit PayeeTransferred(fundCollectorWallet, newPayee);
    }

    function collectETH() external onlyOwner {

        uint256 fundsToSend = address(this).balance;
        bool sent = payable(fundCollectorWallet).send(fundsToSend);
        require(sent, "Failed to send Ether");

        emit ETHCollected(fundCollectorWallet, fundsToSend);
    }

    function withdrawOtherTokens(address _token) external onlyOwner {
        require(_token != address(0), "can't withdraw zero token");
        uint256 fundsToSend;
        if (IERC20(_token) == r33lzToken) {
            fundsToSend =
                r33lzToken.balanceOf(address(this)) -
                totalTokensSold;
        } else {
            fundsToSend = IERC20(_token).balanceOf(address(this));
        }
        IERC20(_token).transfer(msg.sender, fundsToSend);

        emit IERC20TokenWithdrawn(msg.sender, fundsToSend);
    }

    function collectUSDT() external onlyOwner {
        uint256 fundsToSend = USDT.balanceOf(address(this));
        IERC20(USDT).transfer(fundCollectorWallet, fundsToSend);

        emit USDTWithdrawn(fundCollectorWallet, fundsToSend);
    }
}

// File: OpiPets/ETHPriceFeeds.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

interface AggregatorV3Interface {
  function decimals() external view returns (uint8);

  function description() external view returns (string memory);

  function version() external view returns (uint256);

  function getRoundData(uint80 _roundId)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

  function latestRoundData()
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );
}

contract PriceConsumerV3 {
    AggregatorV3Interface internal priceFeed;

    /**
     * Network: ETH Mainnet
     * Aggregator: ETH/USD
     * Address: 0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419
     */
     /*
     * Network: Goerli Testnet
     * Aggregator: ETH/USD
     * Address: 0xD4a33860578De61DBAbDc8BFdb98FD742fA7028e
     */
    constructor() {
        priceFeed = AggregatorV3Interface(
            0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419
        );
    }

    /**
     * Returns the latest price.
     */
    function getLatestPrice() public view returns (int) {
        // prettier-ignore
        (
            /* uint80 roundID */,
            int price,
            /*uint startedAt*/,
            /*uint timeStamp*/,
            /*uint80 answeredInRound*/
        ) = priceFeed.latestRoundData();
        return price;
    }
}
// File: OpiPets/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;


/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
// File: OpiPets/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

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: OpiPets/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

interface IERC20 {

    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: OpiPets/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^0.8.18;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// File: OpiPets/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.18;

import "./Context.sol";

/**
 * @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. This
 * can later be changed with {transferOwnership}.
 *
 * 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.
 */
contract Ownable is Context {
    address private _owner;
    address private _previousOwner;
    uint256 private _lockTime;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

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

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

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}