Enumeration<TreePath> getExpandedDescendants(GroupPath gp) {
		TreePath path = getTreePathFromGroup(gp);
		if (path != null) {
			return getExpandedDescendants(path);
		}
		return null;
	}
Returns an Enumeration of the descendants of gp that are
currently expanded. If path is not currently expanded, this will
return null. If you expand/collapse nodes while iterating over the
returned Enumeration this may not return all the expanded paths, or
may return paths that are no longer expanded.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramDnDTree.java