testDismiss() {
    const ds = new MockDS();
    const rend = new TestRend();
    /** @suppress {checkTypes} suppression added to enable type checking */
    const select = new MockSelect();

    // dismiss empty
    let ac = new AutoComplete(ds, rend, select);
    let dismissed = 0;
    handler.listen(ac, AutoComplete.EventType.DISMISS, () => {
      dismissed++;
    });
    ac.dismiss();
    assertEquals(1, dismissed);

    ac = new AutoComplete(ds, rend, select);
    ac.setToken('sir not seen in this picture');
    ac.dismiss();

    // dismiss with contents
    ac = new AutoComplete(ds, rend, select);
    ac.setToken('t');
    ac.dismiss();
  }
Dismiss when empty and non-empty