'Ensure an invalid operator returns a Bad Request.
GET /groups/{groupid}/users?password_expires_at=
{invalid_operator}:{timestamp}
GET /groups/{group_id}/users?password_expires_at=
{operator}:{timestamp}&{invalid_operator}:{timestamp}'

def test_list_users_in_group_by_password_expires_bad_operator_fails(self):

    bad_op_url = self._list_users_in_group_by_password_expires_at(self._format_timestamp(self.starttime), 'bad')
    self.get(bad_op_url, expected_status=http_client.BAD_REQUEST)
    bad_op_url = self._list_users_in_group_by_multiple_password_expires_at(self._format_timestamp(self.starttime), 'lt', self._format_timestamp(self.starttime), 'x')
    self.get(bad_op_url, expected_status=http_client.BAD_REQUEST)
