private @Nullable Object findLastElement(String s) {
    final String _s = s.trim();
    for (ListIterator<?> it = getElementIterator(getElementCount()); it.hasPrevious(); ) {
      final Object element = it.previous();
      if (isMatchingElement(element, _s)) return element;
    }
    return null;
  }
private @Nullable Object findLastElement(String s)