def head(self, limit=25, **fetch_kwargs):
        """
        shortcut to fetch the first few entries from query expression.
        Equivalent to fetch(order_by="KEY", limit=25)
        :param limit:  number of entries
        :param fetch_kwargs: kwargs for fetch
        :return: query result
        """
        return self.fetch(order_by="KEY", limit=limit, **fetch_kwargs)
shortcut to fetch the first few entries from query expression.
        Equivalent to fetch(order_by="KEY", limit=25)
        :param limit:  number of entries
        :param fetch_kwargs: kwargs for fetch
        :return: query result