anchor.diff:        Result := False;
   
         SetLength(Data, 2);
  -      FH := FixedHeader(TMQTTMessageType.PINGREQ, 0, 0, 0);
  +      FH := FixedHeader(MQTT.PINGREQ, 0, 0, 0);
         RL := 0;
         Data[0] := FH;
         Data[1] := RL;
  
positive.code:       VH: TBytes;
        Payload: TUTF8Text;
      begin
        FH := FixedHeader(TMQTTMessageType.SUBSCRIBE, 0, 1, 0);
        VH := VariableHeaderSubscribe;
        Result := (FMessageID - 1);
        SetLength(Payload, 0);
  
negative.code:       Result := False;
  
        SetLength(Data, 2);
        Data[0] := FixedHeader(MQTT.DISCONNECT, 0, 0, 0);
        Data[1] := 0;
        if SocketWrite(Data) then
          begin
  