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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 cache(self):
 """Get the Django cache interface. This allows disabling the cache with settings.USE_DRF_INSTANCE_CACHE=False. It also delays import so that Django Debug Toolbar will record cache requests. """

        if not self._cache:
            use_cache = getattr(settings, 'USE_DRF_INSTANCE_CACHE', True)
            if use_cache:
                from django.core.cache import cache
                self._cache = cache
        return self._cache