code: private synchronized void createConsumerThreadPool() {
          if (TraceComponent.isAnyTracingEnabled()
              && tc.isEntryEnabled())
              SibTr.entry(tc, "createConsumerThreadPool");
          if (_consumerThreadPool == null) {
              // 214163 Add a threadpool listener to associate threads in trace
              // with the messaging engine.
              _consumerThreadPool = new ThreadPool(
                              "Consumer " + getMessagingEngineName(),
                              0,
                              _customProperties.get_max_consumer_threadpool_size(),
                              new ThreadPoolListener[] { new ThreadPoolListenerImpl(this) });
              _consumerThreadPool
                              .setRequestBufferExpansionLimit(Integer.MAX_VALUE);
          }
          if (TraceComponent.isAnyTracingEnabled()
              && tc.isEntryEnabled())
              SibTr.exit(tc, "createConsumerThreadPool");
      }
docs: If the consumer thread pool hasn't been created, create one here.