code: public boolean isSet(_Fields field) {
      if (field == null) {
        throw new java.lang.IllegalArgumentException();
      }
  
      switch (field) {
      case TRACE_ID:
        return isSetTrace_id();
      case NAME:
        return isSetName();
      case ID:
        return isSetId();
      case PARENT_ID:
        return isSetParent_id();
      case ANNOTATIONS:
        return isSetAnnotations();
      case BINARY_ANNOTATIONS:
        return isSetBinary_annotations();
      case DEBUG:
        return isSetDebug();
      case TIMESTAMP:
        return isSetTimestamp();
      }
      throw new java.lang.IllegalStateException();
    }
docs: Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise