code: public AllWindowedStream<T, GlobalWindow> countWindowAll(long size) {
  		return windowAll(GlobalWindows.create()).trigger(PurgingTrigger.of(CountTrigger.of(size)));
  	}
docs: Windows this {@code DataStream} into tumbling count windows.
  
  <p>Note: This operation is inherently non-parallel since all elements have to pass through
  the same operator instance.
  
  @param size The size of the windows in number of elements.