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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 class_filter(classes, class_name):
 """ Filter classes by comparing two lists. :param classes: matrix classes :type classes: list :param class_name: sub set of classes :type class_name : list :return: filtered classes as list """

    result_classes = classes
    if isinstance(class_name, list):
        if set(class_name) <= set(classes):
            result_classes = class_name
    return result_classes