code: public void clickOnItem(int index) {
      ShadowListView shadowListView = Shadow.extract(realAlertDialog.getListView());
      shadowListView.performItemClick(index);
    }
docs: Simulates a click on the {@code Dialog} item indicated by {@code index}. Handles both multi- and single-choice dialogs, tracks which items are currently
  checked and calls listeners appropriately.
  
  @param index the index of the item to click on