//import Foundation
//
//class TCPMutablePacket: IPMutablePacket {
//    var sourcePort: Port {
//        get {
//            return Port(bytesInNetworkOrder: payload.bytes.advancedBy(IPHeaderLength))
//        }
//        set {
//            setPort(sourcePort, newPort: newValue, at: 0)
//        }
//    }
//
//    var destinationPort: Port {
//        get {
//            return Port(bytesInNetworkOrder: payload.bytes.advancedBy(IPHeaderLength + 2))
//        }
//        set {
//            setPort(destinationPort, newPort: newValue, at: 2)
//        }
//    }
//
//    override func updateChecksum(oldValue: UInt16, newValue: UInt16, type: ChangeType) {
//        super.updateChecksum(oldValue, newValue: newValue, type: type)
//        updateChecksum(oldValue, newValue: newValue, at: IPHeaderLength + 16)
//    }
//
//    // swiftlint:disable:next variable_name
//    private func setPort(oldPort: Port, newPort: Port, at: Int) {
//        payload.replaceBytesInRange(NSRange(location: at + IPHeaderLength, length: 2), withBytes: newPort.bytesInNetworkOrder, length: 2)
//        updateChecksum(oldPort.valueInNetworkOrder, newValue: newPort.valueInNetworkOrder, type: .Port)
//    }
//}