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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def episodes(self):
 """Return a flat episode iterator. :returns: Iterator :code:`((season_num, episode_num), Episode)` :rtype: iterator """


        for sk, season in iteritems(self.seasons):
            # Yield each episode in season
            for ek, episode in iteritems(season.episodes):
                yield (sk, ek), episode