<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def instant_articles(self, **kwargs):
 """ QuerySet including all published content approved for instant articles. Instant articles are configured via FeatureType. FeatureType.instant_article = True. """

        eqs = self.search(**kwargs).sort('-last_modified', '-published')
        return eqs.filter(InstantArticle())