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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 ListField(field):
 """ This wraps a field so that when get_from_instance is called, the field's values are iterated over """

    # alter the original field's get_from_instance so it iterates over the
    # values that the field's get_from_instance() method returns
    original_get_from_instance = field.get_from_instance

    def get_from_instance(self, instance):
        for value in original_get_from_instance(instance):
            yield value

    field.get_from_instance = MethodType(get_from_instance, field)

    return field