def get_cache_expiration(self, request, instance, placeholder):
        now = timezone.now()
        return now + timedelta(seconds=40)
Content is only valid until 40 seconds from now.
dataset/ETHPy150Open divio/django-cms/cms/test_utils/project/pluginapp/plugins/caching/cms_plugins.py/DateTimeCacheExpirationPlugin.get_cache_expiration