shadows/framework/src/main/java/org/robolectric/shadows/ShadowAlertDialog.java
public void clickOnItem(int index) {
    ShadowListView shadowListView = Shadow.extract(realAlertDialog.getListView());
    shadowListView.performItemClick(index);
  }
public void clickOnItem(int index) {
    ShadowListView shadowListView = Shadow.extract(realAlertDialog.getListView());
    shadowListView.performItemClick(index);
  }
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