@Override
    public List<Object> apply(ConsumerRecord<K, V> record) {
        List<Object> vals = func.apply(record);
        if (vals == null) {
            return null;
        }
        KafkaTuple ret = new KafkaTuple();
        ret.addAll(vals);
        return ret.routedTo(stream);
    }
@Test
    public void testNullTranslation() {
        SimpleRecordTranslator<String, String> trans =
                new SimpleRecordTranslator<>((r) -> null, new Fields("key"));
        assertNull(trans.apply(null));
    }