String result2 = popularWordHelper.getCacheKey(seed, tags2, roles, fields, excludes);

        assertEquals(result1, result2);
    }

    public void test_getCacheKey_nullSeed() {
        String seed = null;
        String[] tags = { "tag1" };
        String[] roles = { "role1" };
        String[] fields = { "field1" };
        String[] excludes = { "exclude1" };