docs: @Deprecated
  	public SingleOutputStreamOperator<T> assignTimestamps(TimestampExtractor<T> extractor) {
  		// match parallelism to input, otherwise dop=1 sources could lead to some strange
  		// behaviour: the watermark will creep along very slowly because the elements
  		// from the source go to each extraction operator round robin.
  		int inputParallelism = getTransformation().getParallelism();
  		ExtractTimestampsOperator<T> operator = new ExtractTimestampsOperator<>(clean(extractor));
  		return transform("ExtractTimestamps", getTransformation().getOutputType(), operator)
  				.setParallelism(inputParallelism);
  	}