def get_cache_expiration(self, request, instance, placeholder):
        return 50
Regression test for https://github.com/astropy/astropy/issues/2463
dataset/ETHPy150Open divio/django-cms/cms/test_utils/project/pluginapp/plugins/caching/cms_plugins.py/TTLCacheExpirationPlugin.get_cache_expiration--crossover with--dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/tests/test_core.py/TestFileFunctions.test_write_bytesio