windowStateTable not working properly

[yj-1plusx]

Hi, thanks for the great library!

One problem I encountered was when I tried to test a TumblingWindow aggregation.
Let's say I create a 2 second tumbling window like so:
val w = TimeWindows .of(TimeUnit.SECONDS.toMillis(2)) .advanceBy(TimeUnit.SECONDS.toMillis(2)) .until(TimeUnit.SECONDS.toMillis(2))

Now, I use the CustomTimestampExtractor and send in events with value "number@timestamp", e.g.
("a", "1@1000"), ("a", "1@1500"), ("a", "1@2000"), ("a", "1@10000"), ("a", "1@100")
I run a simple count aggregation and would expect count to be (0->2), (2000->1), (10000->1), because the last event arrives when the time window [0,2000) is already closed because of until(2000). However, the last event is accounted for.
Could this be an interpretation, that the until duration is understood as a lower bound?

Thanks