def METHOD_NAME(self, key):
    """Return either an ExampleNode or ExampleParentNode"""
    childdata = self.get_value()['children'][key]
    childdepth = self.get_depth() + 1
    if 'children' in childdata:
        childclass = ExampleParentNode
    else:
        childclass = ExampleNode
    return childclass(childdata, parent=self, key=key, depth=childdepth)