Ensemble2Auto reliability test failed with OOM after less than 3 hours.
Heap dump file shows that heap is mostly occupied by BorderPane (62Mb) and
GridPane (51Mb). The path to GC root shows that these objects are referenced
from ensemble.samples.animation.timelines.TimelineEventSample$1 which are
not removed from javafx.animation.AnimationTimer[] for some reason.

Instrumenting AbstractMasterTimer and AnimationTimer classes shows that every
time we click on TimelineEvents sample ensemble.samples.animation.timelines.TimelineEventSample$1
is added twice while when we switch to another tab it is removed only once.
The reason is because sample.play() is called twice from ensemble.pages.SamplePage:
 149 sample.play();
 213 sample.play();

while sample.stop() is called only once:
 215 sample.stop();


javafx.animation.AnimationTimer[] doesn't check for uniqueness, so the number of times
we call play() and stop() methods should be equal. This needs to be fixed in Ensemble2.

I will try to patch my local version of Ensemble and remove first call of play()
and run Ensemble2Auto to see how much it helps.
I am not sure this is correct fix, so it should be up to Ensemble developers to fix it properly.