@staticmethod
def unpack_subitems(value):
    """
        Function that parses response from source and yield items found in value.
        This can be overridden and adapted to the controller it is to be used in.

        Example::

            def parse_response(self, response):
                for parser in self.get_parsers():
                    if parser.can_unpack_subitems(response):
                        yield from parser.unpack_subitems(response)

        """
    yield None
