    if (params.permitData.length > 0) {
        (ISignatureTransfer.PermitTransferFrom memory permit, bytes memory signature) =
            abi.decode(params.permitData, (ISignatureTransfer.PermitTransferFrom, bytes));
        permit2.permitTransferFrom(
            permit,
            ISignatureTransfer.SignatureTransferDetails(address(this), state.liquidatorCost),
            msg.sender,
            signature
        );
    } else {
        // take value from liquidator
        SafeERC20.safeTransferFrom(IERC20(asset), msg.sender, address(this), state.liquidatorCost);
    }
interface ISignatureTransfer is IEIP712 {
    /// @notice The token and amount details for a transfer signed in the permit transfer signature
    struct TokenPermissions {
        // ERC20 token address
        address token;
        // the maximum amount that can be spent
        uint256 amount;
    }

    /// @notice The signed permit message for a single token transfer
    struct PermitTransferFrom {
        TokenPermissions permitted;
        // a unique value for every token owner's signature to prevent signature replays
        uint256 nonce;
        // deadline on the permit signature
        uint256 deadline;
    }
}
    if (params.permitData.length > 0) {
        (ISignatureTransfer.PermitTransferFrom memory permit, bytes memory signature) =
            abi.decode(params.permitData, (ISignatureTransfer.PermitTransferFrom, bytes));
        require(permit.permitted.token == asset, "V3Vault: invalid token");
        //@permitted amount is checked inside uniswap Permit2
        permit2.permitTransferFrom(
            permit,
            ISignatureTransfer.SignatureTransferDetails(address(this), state.liquidatorCost),
            msg.sender,
            signature
        );
    } else {
        // take value from liquidator
        SafeERC20.safeTransferFrom(IERC20(asset), msg.sender, address(this), state.liquidatorCost);
    }
