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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 unregister(self, model_or_iterable):
 """ Remove a model or a list of models from the list of models whose comments will be moderated. Raise ``NotModerated`` if any of the models are not currently registered for moderation. """

        if isinstance(model_or_iterable, ModelBase):
            model_or_iterable = [model_or_iterable]
        for model in model_or_iterable:
            if model not in self._registry:
                raise NotModerated("The model '%s' is not currently being moderated" % model._meta.module_name)
            del self._registry[model]