Check if user is a subscribed of specified list

        :param list_id: list ID number
        :param user_id: user ID number
        :return: :code:`True` if user is subscribed of list, :code:`False` otherwise

def is_subscribed_list(self, list_id, user_id):
        """
        Check if user is a subscribed of specified list

        :param list_id: list ID number
        :param user_id: user ID number
        :return: :code:`True` if user is subscribed of list, :code:`False` otherwise
        """
        try:
            return bool(self._client.show_list_subscriber(list_id=list_id, user_id=user_id))
        except TweepError as e:
            if e.api_code == TWITTER_USER_IS_NOT_LIST_MEMBER_SUBSCRIBER:
                return False
            raise