I would like to change purgeOptions.age of a StreamLayer after it was already added to the map:
layer.purgeOptions.age = 1;
But the value is just ignored and older graphics are not removed.
On the other hand if I set purgeOptions.displayCount to a fixed value it works as expected.
It also works if I set purgeOptions.age before the StreamLayer is added to the map. But unfortunately that is not an option for my current use case.