def load_child_node(self, key):
        raise TreeWidgetError("virtual function.  Implement in subclass")
Returns a serialized form of the schema of the resource.
dataset/ETHPy150Open AnyMesh/anyMesh-Python/example/urwid/treetools.py/ParentNode.load_child_node--crossover with--dataset/ETHPy150Open toastdriven/piecrust/piecrust/resources.py/Resource.get_schema