nodes: 0, module; 1, function_definition; 2, function_name:class_variables; 3, parameters; 4, block; 5, identifier:self; 6, expression_statement; 7, expression_statement; 8, return_statement; 9, comment:"""
          Returns all documented class variables in the class, sorted
          alphabetically as a list of `pydoc.Variable`.
          """; 10, assignment; 11, call; 12, identifier:p; 13, lambda; 14, identifier:filter; 15, argument_list; 16, lambda_parameters; 17, boolean_operator; 18, identifier:p; 19, call; 20, identifier:o; 21, call; 22, call; 23, attribute; 24, argument_list; 25, identifier:isinstance; 26, argument_list; 27, attribute; 28, argument_list; 29, attribute; 30, identifier:values; 31, identifier:o; 32, identifier:Variable; 33, attribute; 34, identifier:_docfilter; 35, identifier:o; 36, identifier:self; 37, identifier:doc; 38, identifier:self; 39, identifier:module
code: def class_variables(self):
          """
          Returns all documented class variables in the class, sorted
          alphabetically as a list of `pydoc.Variable`.
          """
          p = lambda o: isinstance(o, Variable) and self.module._docfilter(o)
          return filter(p, self.doc.values())