code: @Override
  	public void processElement2(StreamRecord<T2> record) throws Exception {
  		processElement(record, rightBuffer, leftBuffer, -upperBound, -lowerBound, false);
  	}
docs: Process a {@link StreamRecord} from the right stream. Whenever a {@link StreamRecord}
  arrives at the right stream, it will get added to the right buffer. Possible join candidates
  for that element will be looked up from the left buffer and if the pair lies within the user
  defined boundaries, it gets passed to the {@link ProcessJoinFunction}.
  
  @param record An incoming record to be joined
  @throws Exception Can throw an exception during state access