Windowed operator configuration

Because we are developing an application for a taxi driver looking for passengers, we are only interested in the last few minutes of data, to have a good advice for the driver where to look. We are accumulating the data in 5-minute sliding windows that slide by 1 minute so that we always use the data from the past 5 minutes for our service. In Application.java:

KeyedWindowedOperatorImpl<String, Double, MutableDouble, Double> windowedOperator 
  = new KeyedWindowedOperatorImpl<>();
    
// 5-minute windows slide by 1 minute
windowedOperator.setWindowOption(new WindowOption.TimeWindows(Duration.standardMinutes(5)).slideBy(Duration
  .standardMinutes(1)));
    
// Because we only care about the last 5 minutes, lateness horizon 
// is set to 4 minutes since the watermark is set to one minute before 
// the latest timestamp.
windowedOperator.setAllowedLateness(Duration.standardMinutes(4));  

We are now setting the accumulation to be a SumDouble, which...