def patch_children(self, node, tree):
        "Patch Viewtree based on children of SizeTree."
        for subnode in node.children:
            child = tree.pop_child(subnode.name)
            if child is None:
                # Directory is gone.
                subnode.delete()
            else:
                # Dig down further in tree.
                self.__progress.step()
                self.patch_tree(subnode, child)
Patch Viewtree based on children of SizeTree.
recipes/Python/577633_Directory_Pruner_2/recipe-577633.py