docs: public FlinkKafkaConsumerBase<T> assignTimestampsAndWatermarks(AssignerWithPunctuatedWatermarks<T> assigner) {
  		checkNotNull(assigner);
  
  		if (this.periodicWatermarkAssigner != null) {
  			throw new IllegalStateException("A periodic watermark emitter has already been set.");
  		}
  		try {
  			ClosureCleaner.clean(assigner, true);
  			this.punctuatedWatermarkAssigner = new SerializedValue<>(assigner);
  			return this;
  		} catch (Exception e) {
  			throw new IllegalArgumentException("The given assigner is not serializable", e);
  		}
  	}