def _do_open_node(self, node):
        if self.hide_root and node is self.root:
            height = 0
        else:
            self.add_widget(node)
            height = node.height
            if not node.is_open:
                return height
        for cnode in node.nodes:
            height += self._do_open_node(cnode)
        return height
dataset/ETHPy150Open kivy/kivy/kivy/uix/treeview.py/TreeView._do_open_node/original