how to creat CountDownTimer outside onCreate(Bundle) in android studio java?

after I surround object of CountDownTimer class with curly braces ,,the code is working correctly ,, is there any explanation ?

`

public class MainActivity extends AppCompatActivity {  

{
    new CountDownTimer(30000, 1000) {

        public void onTick(long millisUntilFinished) {
            Log.i("countDownTimer count","1000 millisecond passed");
           
        }

        public void onFinish() {
            Log.i("countDowntimer count","30 Seconds passed, Timer has Finished");
           
        }
    }.start();
}


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);        

}}

`