def build_class(self):
            """
            Finalize class based on the accumulated configuration.

            Builder cannot be used after calling this method.
            """
            if self._slots is True:
                return self._create_slots_class()

            return self.abc.update_abstractmethods(
                self._patch_original_class()
            )

            Finalize class based on the accumulated configuration.

            Builder cannot be used after calling this method.
            
lib/attr/_make.py