@classmethod<EOL><INDENT>def _update_kind_map(cls):<DEDENT>
cls._kind_map[cls._class_name()] = cls<EOL>class_key = cls._class_key()<EOL>if class_key:<EOL><INDENT>cls._class_map[tuple(class_key)] = cls<EOL><DEDENT>
Override; called by Model._fix_up_properties().

        Update the kind map as well as the class map, except for PolyModel
        itself (its class key is empty).  Note that the kind map will
        contain entries for all classes in a PolyModel hierarchy; they all
        have the same kind, but different class names.  PolyModel class
        names, like regular Model class names, must be globally unique.