shadows/framework/src/main/java/org/robolectric/shadows/ShadowToast.java
public static boolean showedToast(CharSequence message) {
    ShadowApplication shadowApplication = Shadow.extract(RuntimeEnvironment.application);
    for (Toast toast : shadowApplication.getShownToasts()) {
      ShadowToast shadowToast = Shadow.extract(toast);
      String text = shadowToast.text;
      if (text != null && text.equals(message.toString())) {
        return true;
      }
    }
    return false;
  }
public static boolean showedToast(CharSequence message) {
    ShadowApplication shadowApplication = Shadow.extract(RuntimeEnvironment.application);
    for (Toast toast : shadowApplication.getShownToasts()) {
      ShadowToast shadowToast = Shadow.extract(toast);
      String text = shadowToast.text;
      if (text != null && text.equals(message.toString())) {
        return true;
      }
    }
    return false;
  }
query method that returns whether or not a particular {@code Toast} has been shown.

@param message the message to search for
@return whether the {@code Toast} was requested