code: protected synchronized void groupCloseNotification(Conversation conversation, 
                                                        ProxyQueueConversationGroup group)
     {
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.entry(tc, "groupCloseNotification", new Object[] {conversation, group});
        if (convToGroupMap.remove(conversation) == null)
        {
           if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) SibTr.debug(tc, "group unknown!");
        }
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.exit(tc, "groupCloseNotification");
     }
docs: Called by a proxy queue conversation group to notify this
  factory of its closure.
  @param conversation
  @param group