String[] fields = { "field2", "field1" };
        String[] excludes = { "exclude2", "exclude1" };

        String result1 = popularWordHelper.getCacheKey(seed, tags, roles, fields, excludes);
        String result2 = popularWordHelper.getCacheKey(seed, tags, roles, fields, excludes);

        assertEquals(result1, result2);
    }

    @Test
    public void test_getCacheKey_differentOrder() {