Context: I have the heapwalker open, I have selected a class and performed "show in instances view".

Use case: When looking through the references of the class to find out 
who is holding onto the class, I am generally not interested in any "loop" references.
Filtering these out would immediately make my job a whole lot easier.

Possible solution: provide a checkbox next to the "loop" icon at the bottom right.
When the checkbox is de-selected, remove all nodes in the tree where the node is a "loop" node.
Also remove any nodes that not longer have children (except for the root node).