code: @PublicEvolving
  	public void setStreamTimeCharacteristic(TimeCharacteristic characteristic) {
  		this.timeCharacteristic = Preconditions.checkNotNull(characteristic);
  		if (characteristic == TimeCharacteristic.ProcessingTime) {
  			getConfig().setAutoWatermarkInterval(0);
  		} else {
  			getConfig().setAutoWatermarkInterval(200);
  		}
  	}
docs: Sets the time characteristic for all streams create from this environment, e.g., processing
  time, event time, or ingestion time.
  
  <p>If you set the characteristic to IngestionTime of EventTime this will set a default
  watermark update interval of 200 ms. If this is not applicable for your application
  you should change it using {@link ExecutionConfig#setAutoWatermarkInterval(long)}.
  
  @param characteristic The time characteristic.