def test_ref_get_with_invalid_election_id_non_existent_election_id(self):
        response = self.client.get(
            reverse('results-export'),
            { 'election': '69' },
            HTTP_REFERER=reverse('results'),
            follow=True
        )

        messages = list(response.context['messages'])
        self.assertEqual(
            messages[0].message,
            'You specified an ID for a non-existent election.'
        )
        self.assertRedirects(response, reverse('results'))
def addOperators(self, num, target):
        """
        Adapted from https://leetcode.com/discuss/58614/java-standard-backtrace-ac-solutoin-short-and-clear

        Algorithm:
        1. DFS
        2. Special handling for multiplication
        3. Detect invalid number with leading 0's
        :type num: str
        :type target: int
        :rtype: List[str]
        """
        ret = []
        self.dfs(num, target, 0, "", 0, 0, ret)
        return ret