@Override
  public Event supply() {
    PipeRealtimeEvent realtimeEvent = (PipeRealtimeEvent) pendingQueue.directPoll();

    while (realtimeEvent != null) {
      final Event suppliedEvent;

      // Used to judge the type of the event, not directly for supplying.
      final Event eventToSupply = realtimeEvent.getEvent();
      if (eventToSupply instanceof TabletInsertionEvent) {
        suppliedEvent = supplyTabletInsertion(realtimeEvent);
      } else if (eventToSupply instanceof TsFileInsertionEvent) {
        suppliedEvent = supplyTsFileInsertion(realtimeEvent);
      } else if (eventToSupply instanceof PipeHeartbeatEvent) {
        suppliedEvent = supplyHeartbeat(realtimeEvent);
      } else if (eventToSupply instanceof PipeDeleteDataNodeEvent
          || eventToSupply instanceof ProgressReportEvent) {
        suppliedEvent = supplyDirectly(realtimeEvent);
      } else {
        throw new UnsupportedOperationException(
            String.format(
                "Unsupported event type %s for hybrid realtime extractor %s to supply.",
                eventToSupply.getClass(), this));
      }

      realtimeEvent.decreaseReferenceCount(
          PipeRealtimeDataRegionHybridExtractor.class.getName(), false);

      if (suppliedEvent != null) {
        return suppliedEvent;
      }

      realtimeEvent = (PipeRealtimeEvent) pendingQueue.directPoll();
    }

    // Means the pending queue is empty.
    return null;
  }
These judgements are deprecated, and are only reserved for manual operation and compatibility.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/extractor/dataregion/realtime/PipeRealtimeDataRegionHybridExtractor.java