`assignTimestampsAndWatermarks` before `keyBy` works:
```java
DataStream<Trip> trips =
env.addSource(consumer).assignTimestampsAndWatermarks(new
BoundedOutOfOrdernessTimestampExtractor<Trip>(Time.days(1)) {
@Override
public long extractTimestamp(Trip trip) {
return trip.endTime.getTime();
}
});
KeyedStream<Trip, Long> userTrips = trips.keyBy(trip -> trip.userId);
DataStream<FeaturizedTrip> featurizedUserTrips = userTrips.process(new
Featurization());
AllWindowedStream<FeaturizedTrip, TimeWindow> windowedUserTrips =
featurizedUserTrips.timeWindowAll(Time.days(7),
Time.days(1));
```
But not after `keyBy` and `process`:
```java
DataStream<Trip> trips = env.addSource(consumer);
KeyedStream<Trip, Long> userTrips = trips.keyBy(trip -> trip.userId);
DataStream<FeaturizedTrip> featurizedUserTrips =
userTrips.process(new
Featurization()).assignTimestampsAndWatermarks(new
BoundedOutOfOrdernessTimestampExtractor<FeaturizedTrip>(Time.days(1)) {
@Override
public long extractTimestamp(FeaturizedTrip trip) {
return trip.endTime.getTime();
}
});
AllWindowedStream<FeaturizedTrip, TimeWindow> windowedUserTrips =
featurizedUserTrips.timeWindowAll(Time.days(7),
Time.days(1));
```
Windows are never triggered.
Is it a bug or expected behavior? If the latter, where is it documented?
