code: @TargetApi(Build.VERSION_CODES.FROYO)
      @Nullable
      public static ArrayList<CharSequence> optCharSequenceArrayList(@Nullable Bundle bundle, @Nullable String key) {
          return optCharSequenceArrayList(bundle, key, new ArrayList<CharSequence>());
      }
docs: Since Bundle#getCharSequenceArrayList returns concrete ArrayList type, so this method follows that implementation.