@Override
    public boolean equals(Object that) {
      if (that == null)
        return false;
      if (that instanceof echo_args)
        return this.equals((echo_args)that);
      return false;
    }
Returns true if field corresponding to fieldID 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