@Override
    public TaskMode deserialize(JsonParser jsonParser, DeserializationContext context)
        throws IOException, JsonProcessingException {
      ObjectCodec oc = jsonParser.getCodec();
      JsonNode node = oc.readTree(jsonParser);
      if (node == null || node.textValue().equals("")) {
        return TaskMode.Active;
      } else {
        return TaskMode.valueOf(node.textValue());
      }
    }
@return Returns a new ObjectMapper that's been configured to (de)serialize
        Samza's job data model, and simple data types such as TaskName,
        Partition, Config, and SystemStreamPartition.
samza-core/src/main/java/org/apache/samza/serializers/model/SamzaObjectMapper.java