code: 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");
    }
docs: Message that was requested by this consumer has been locked.
  Note that it could have been locked by some other consumer.
  This method will never be called for messages received due to gets issued by the
  RemoteQPConsumerKeyGroup
  @param key