'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).'

@classmethod
def _class_name(cls):

    return cls._get_kind()
