public Object getFieldValue(_Fields field) {
      switch (field) {
      case MESSAGE:
        return getMessage();

      }
      throw new IllegalStateException();
    }
Returns true if field message is set (has been assigned a value) and false otherwise
agent-module/agent-testweb/thrift-plugin-testweb/src/main/java/com/pinpoint/test/plugin/dto/EchoService.java