@classmethod<EOL><INDENT>def _class_name(cls):<DEDENT>
return cls._get_kind()<EOL>
A hook for polymodel to override.

        For regular models and expandos this is just an alias for
        _get_kind().  For PolyModel subclasses, it returns the class name
        (as set in the 'class' attribute thereof), whereas _get_kind()
        returns the kind (the class name of the root class of a specific
        PolyModel hierarchy).