private void swingFireRootChanged() {
		TreeModelEvent event = new TreeModelEvent(this, (TreePath) null);
		for (TreeModelListener listener : listeners) {
			listener.treeStructureChanged(event);
		}
	}
Sets the models root node. NOTE: this is intended to only be called from the {@link GTree}
@param newRoot the new tree model root.  It will either be the actual root or a root
of a filtered sub-tree
Ghidra/Framework/Docking/src/main/java/docking/widgets/tree/internal/GTreeModel.java