function doSellerCancel(
        bytes16 _tradeID,
        address _seller,
        address _buyer,
        uint256 _value,
        uint16 _fee,
        uint128 _additionalGas
    ) private returns (bool) {
        Escrow memory _escrow;
        bytes32 _tradeHash;
        (_escrow, _tradeHash) = getEscrowAndHash(_tradeID, _seller, _buyer, _value, _fee);
        if (!_escrow.exists) {
            return false;
        }
        if(_escrow.sellerCanCancelAfter <= 1 || _escrow.sellerCanCancelAfter > block.timestamp) {
            return false;
        }
        uint128 _gasFees = _escrow.totalGasFeesSpentByRelayer
            + (msg.sender == relayer
                ? (GAS_doSellerCancel + _additionalGas ) * uint128(tx.gasprice)
                : 0
            );
        delete escrows[_tradeHash];
        emit CancelledBySeller(_tradeHash);
        transferMinusFees(_seller, _value, _gasFees, 0);
        return true;
    }