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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 peek_record(self, model_class, record_id):
 """Return an instance of the model_class from the cache if it is present. Args: model_class (:class:`cinder_data.model.CinderModel`):
 A subclass of :class:`cinder_data.model.CinderModel` of your chosen model. record_id (int):
 The id of the record requested. Returns: :class:`cinder_data.model.CinderModel`: An instance of model_class or None. """

        if self._cache:
            return self._cache.get_record(model_class.__name__, record_id)
        else:
            return None