public void setPeriodicWatermarkAssigner(
		AssignerWithPeriodicWatermarks<T> periodicWatermarkAssigner) {
		this.periodicWatermarkAssigner = periodicWatermarkAssigner;
		ClosureCleaner.clean(this.periodicWatermarkAssigner, true);
	}
public void setPeriodicWatermarkAssigner ( AssignerWithPeriodicWatermarks < T > periodicWatermarkAssigner ) { this . periodicWatermarkAssigner = periodicWatermarkAssigner ; ClosureCleaner . clean ( this . periodicWatermarkAssigner , true ) ; }
Set the assigner that will extract the timestamp from {@link T} and calculate the
watermark.
@param periodicWatermarkAssigner periodic watermark assigner