assertNotNull(result);
        assertTrue(result.isEmpty());
    }

    @Test
    public void test_toLowerHyphen_nullValues() {
        Map<String, Object> source = new HashMap<>();
        source.put("AnotherKey", "anotherValue");
        source.put("ValidKey", "validValue");

        Map<String, Object> result = searchLogHelper.toLowerHyphen(source);

        assertEquals("anotherValue", result.get("another_key"));

		// Forbidden with key not in policy.conditions for signed requests V2.
		{http.StatusForbidden, credentials.SecretKey, map[string]string{"Awsaccesskeyid": credentials.AccessKey, "AnotherKey": "AnotherContent"}},
	}

	for i, test := range testCasesV2 {
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()