nodes: 0, module; 1, function_definition; 2, function_name:sort_untl; 3, parameters; 4, block; 5, identifier:self; 6, identifier:sort_structure; 7, expression_statement; 8, expression_statement; 9, comment:"""Sort the UNTL Python object by the index
          of a sort structure pre-ordered list.
          """; 10, call; 11, attribute; 12, argument_list; 13, attribute; 14, identifier:sort; 15, keyword_argument; 16, identifier:self; 17, identifier:children; 18, identifier:key; 19, lambda; 20, lambda_parameters; 21, call; 22, identifier:obj; 23, attribute; 24, argument_list; 25, identifier:sort_structure; 26, identifier:index; 27, attribute; 28, identifier:obj; 29, identifier:tag
code: def sort_untl(self, sort_structure):
          """Sort the UNTL Python object by the index
          of a sort structure pre-ordered list.
          """
          self.children.sort(key=lambda obj: sort_structure.index(obj.tag))