assertNotNull(items);
        // The cache may work fine even with invalid locale, so check size is reasonable
        assertTrue(items.size() >= 1);
    }

    @Test
    public void test_getHostname_unknownHost() {
        final SystemHelper mockSystemHelper = new SystemHelper() {
            @Override
            protected Map<String, String> getEnvMap() {
                return new HashMap<>();
            }