Weird functionality for expanding/collapsing all tree

[Gustav Gussi]

I need to expand/collapse all tree. With collapsing there are no problems as first (root) keys is know. But what about expanding. It is enough hard to know what last key which I need to use to expand. Is it possible to add 2 methods collapseAll/expandAll?

[Kevin Armstrong]

Added expandAll, collapseAll, withExpandAll and withCollapseAll to TreeViewController