code: protected MESubscription getSubscription(SIBUuid12 topicSpace, String topic)
    {
      return (MESubscription)iProxies.get(BusGroup.subscriptionKey(topicSpace, topic));
    }
docs: Gets the MESubscription represented from this topicSpace and topic
  
  @param topicSpace
  @param topic
  
  @return MESubscription representing this topicSpace/topic