docs: private ITridentPartitionManager getOrCreatePartitionManager(Partition partition) {
      ITridentPartitionManager pm;
      if(!pmMap.containsKey(partition.getId())) {
        IEventHubReceiver receiver = recvFactory.create(spoutConfig, partition.getId());
        pm = pmFactory.create(receiver);
        pmMap.put(partition.getId(), pm);
      }
      else {
        pm = pmMap.get(partition.getId());
      }
      return pm;
    }