Inheritance: PeerMessage
 public RejectRequestMessage(PieceMessage message)
     : this(message.PieceIndex, message.StartOffset, message.RequestLength)
 {
 }
 public HttpRequestData(RequestMessage request)
 {
     Request = request;
     var m = new PieceMessage(request.PieceIndex, request.StartOffset, request.RequestLength);
     TotalToReceive = m.ByteLength;
 }