code: void addConsumer(ConsumerSessionImpl consumer) {
          if (TraceComponent.isAnyTracingEnabled()
              && tc.isEntryEnabled())
              SibTr.entry(tc, "addConsumer", consumer);
  
          _consumerList.add(consumer);
  
          if (TraceComponent.isAnyTracingEnabled()
              && tc.isEntryEnabled())
              SibTr.exit(tc, "addConsumer");
      }
docs: Adds a consumer to the message procoessor's list of consumers.
  
  @param consumer