@Override
    public String toString() {
      StringBuilder sb = new StringBuilder("echo_result(");
      boolean first = true;

      sb.append("success:");
      if (this.success == null) {
        sb.append("null");
      } else {
        sb.append(this.success);
      }
      first = false;
      sb.append(")");
      return sb.toString();
    }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise
agent-module/plugins-it/thrift-it/thrift-0-10-it/src/test/java/com/navercorp/pinpoint/it/plugin/thrift/dto/EchoService.java