On expand/collapse of an entry, the scroll position jumps.
What we would expect is that the collapsed/expanded cell would keep it's position (if possible)

This issue happens since the VirutalFlow rewrite.

According to an older ticket, something similar happened before, but it was less problematic. (https://bugs.openjdk.org/browse/JDK-8087859?jql=text%20~%20%22treeview%22)

I've added a test-class, video and a unit-test.
For the unit-test, I've expanded the existing TreeViewTest, and added my new unit-test at the bottom.