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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 total_review_average(obj, normalize_to=100):
 """Returns the average for all reviews of the given object."""

    ctype = ContentType.objects.get_for_model(obj)
    total_average = 0
    reviews = models.Review.objects.filter(
        content_type=ctype, object_id=obj.id)
    for review in reviews:
        total_average += review.get_average_rating(normalize_to)
    if reviews:
        total_average /= reviews.count()
    return total_average