@Override public List<Object> getStructFieldsDataAsList(Object data) {
      if (data == null) {
        return null;
      }
      int size = getAllStructFieldRefs().size();
      List<Object> res = new ArrayList<>(size);
      for (int i = 0; i < size; i++) {
        res.add(baseOI.getStructFieldData(data, getAllStructFieldRefs().get(i)));
      }
      return res;
    }
returns null for data = null.

@param data input data.
kafka-handler/src/java/org/apache/hadoop/hive/kafka/KafkaSerDe.java