code: def inspect(orm_class, attribute_name):
          
          key = (orm_class, attribute_name)
          elems = OrmAttributeInspector.__cache.get(key)
          if elems is None:
              elems = OrmAttributeInspector.__inspect(key)
              OrmAttributeInspector.__cache[key] = elems
          return elems
docs: :param attribute_name: name of the mapped attribute to inspect.
          :returns: list of 2-tuples containing information about the inspected
            attribute (first element: mapped entity attribute kind; second
            attribute: mapped entity attribute)