docs: private SubscriptionMessageHandler removeSubscription(
      SIBUuid12 topicSpace,
      String topic,
      SubscriptionMessageHandler messageHandler,
      Hashtable subscriptionsTable,
      boolean sendProxy)
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.entry(
          tc,
          "removeSubscription",
          new Object[] {
            topicSpace,
            topic,
            messageHandler,
            subscriptionsTable,
            new Boolean(sendProxy)});
  
      // Get a key to find the Subscription with
      final String key = subscriptionKey(topicSpace, topic);
  
      synchronized( subscriptionLock )
      {
        // Find the subscription from this Buss list of subscriptions.
        final MESubscription subscription = (MESubscription) subscriptionsTable.get(key);
        
        // If the subscription doesn't exist then simply return
        // as this is a Foreign Bus subscription.
        if (subscription == null)
        {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
            SibTr.exit(
              tc,
              "removeSubscription",
              "Non Existent Subscription " + topicSpace + ":" + topic);
          
          return messageHandler;
        }
    
        // Perform the proxy subscription operation.
        messageHandler = doProxySubscribeOp(subscription.removeRef(),
                                            subscription,
                                            messageHandler,
                                            subscriptionsTable,
                                            sendProxy);
      }
      
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.exit(tc, "removeSubscription", messageHandler);
  
      return messageHandler;
    }