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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 by_youtube_id(cls, youtube_id):
 """ Look up video by youtube id """

        qset = cls.objects.filter(
            encoded_videos__profile__profile_name='youtube',
            encoded_videos__url=youtube_id
        ).prefetch_related('encoded_videos', 'courses')
        return qset