follow these steps:
1. expand all
2. move to bottom
3. remove last

after 3, the TreeView will not reset layout, but keep it no change, which result the new last item is not located at bottom of View.

I think it should returnBounds after rowsRemoved, but it not.
flicker's properties are not work on this case.

And second problem:
if expand all items, and scroll to end (vertical direction), at this point, the contentHeight is right.
But, if then collapse all, then the contentHeight is not one line, but like (contentHeight - view.height).

I think the calculation of contentHeight has Bug, maybe there is relation between it and this issue.
and the contentHeight bug maybe is caused by location of first item.
after the collapse, the Y of first item in content should be 0, but not next to the top of view.

and the contentHeight problem will result 'returnToBounds' can't work normally.