def METHOD_NAME(self, expected, dt):
    self.assertEqual(expected, utils.datetime_to_unix(dt))
    with mock.patch.dict(os.environ, {'TZ': 'UTC'}):
        self.assertEqual(expected, utils.datetime_to_unix(dt))
    with mock.patch.dict(os.environ, {'TZ': 'Europe/Paris'}):
        self.assertEqual(expected, utils.datetime_to_unix(dt))
    with mock.patch.dict(os.environ, {'TZ': 'US/Eastern'}):
        self.assertEqual(expected, utils.datetime_to_unix(dt))