'Ensure a invalid timestamp returns a Bad Request.
GET /users?password_expires_at={invalid_timestamp}
GET /users?password_expires_at={operator}:{timestamp}&
{operator}:{invalid_timestamp}'

def test_list_users_by_password_expires_with_bad_timestamp_fails(self):

    bad_ts_url = self._list_users_by_password_expires_at(self.starttime.strftime('%S:%M:%ST%Y-%m-%d'))
    self.get(bad_ts_url, expected_status=http_client.BAD_REQUEST)
    bad_ts_url = self._list_users_by_multiple_password_expires_at(self._format_timestamp(self.starttime), 'lt', self.starttime.strftime('%S:%M:%ST%Y-%m-%d'), 'gt')
    self.get(bad_ts_url, expected_status=http_client.BAD_REQUEST)
