docs: public final void messageLocked(AIStreamKey key)
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) 
        SibTr.entry(this, tc, "messageLocked", key);
      synchronized (this)
      {
        countOfUnlockedMessages--;
              
        if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
            SibTr.debug(tc, "readAhead change: countOfUnlockedMessages-- " + countOfUnlockedMessages);
      }
      try
      {
        if (readAhead)
          tryPrefetching();
      }
      catch (SIResourceException e)
      {
        FFDCFilter.processException(
          e,
          "com.ibm.ws.sib.processor.impl.RemoteQPConsumerKey.messageLocked",
          "1:663:1.47.1.26",
          this);
        SibTr.exception(tc, e);
        // no need to throw this exception, since its only a failure in prefetching
      }
  
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) 
        SibTr.exit(this, tc, "messageLocked");
    }