TreeItem keeps references to TreeViews even though they don't exist any more

TreeItem keeps reference to TreeViews even the latest don't exist anymore.
The attached test run with -Xmx16m fails with OOM after 51 iterations.
Heap dump shows all 51 TreeView exist in the heap.

Steps to run the test:
> compile TreeViewMemTest.java
> java -cp "..." -Xmx16m TreeViewMemTest -mode static

No problems in case the test is run in dynamic mode (-mode dynamic) in which new TreeItem objects are created on each iteration.