When the first data is being received.
      Syntax
         
            public virtual void 
            markReceiving
            ()
         
      
      Returns
void Usage SUPE2ETraceController* TraceHandler = [SUPE2ETraceController sharedController]; SUPE2ETraceTransaction* Trace = [TraceHandler createTransaction]; SUPE2ETraceStep* theStep = [Trace createStep]; SUPE2ETraceRequest* theRequest = [theStep createRequest]; [theRequest markReceiving];