code: public void load(String mask) {
          options.onComplete = object -> CompleteEvent.fire(this, object);
          options.onKeyPress = object -> KeyPressEvent.fire(this, object);
          options.onChange = object -> ChangeEvent.fire(this, object);
          options.onInvalid = (object, event, function, error) -> InvalidEvent.fire(this, object, error[0]);
          $(valueBoxBase.getElement()).mask(mask, options);
      }
docs: Mask the input field with given mask value.