:meth:`.WHashGeneratorProto.generator_family` implementation

def generator_family(cls):
		""" :meth:`.WHashGeneratorProto.generator_family` implementation
		"""
		if cls.__generator_family__ is not None:
			if isinstance(cls.__generator_family__, str) is False:
				raise TypeError('"__generator_class__"  if defined must be a str instance')

		if cls.__generator_family__ is not None:
			return cls.__generator_family__.upper()