Adds a :class:`UserStory` and returns a :class:`UserStory` resource.

        :param subject: subject of the :class:`UserStory`
        :param attrs: other :class:`UserStory` attributes

def add_user_story(self, subject, **attrs):
        """
        Adds a :class:`UserStory` and returns a :class:`UserStory` resource.

        :param subject: subject of the :class:`UserStory`
        :param attrs: other :class:`UserStory` attributes
        """
        return UserStories(self.requester).create(
            self.id, subject, **attrs
        )