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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 convert_all_videos(app_label, model_name, object_pk):
 """ Automatically converts all videos of a given instance. """

    # get instance
    Model = apps.get_model(app_label=app_label, model_name=model_name)
    instance = Model.objects.get(pk=object_pk)

    # search for `VideoFields`
    fields = instance._meta.fields
    for field in fields:
        if isinstance(field, VideoField):
            if not getattr(instance, field.name):
                # ignore empty fields
                continue

            # trigger conversion
            fieldfile = getattr(instance, field.name)
            convert_video(fieldfile)