private @Nullable Object findFirstElement(String s) {
    final String _s = s.trim();
    for (ListIterator<?> it = getElementIterator(0); it.hasNext(); ) {
      final Object element = it.next();
      if (isMatchingElement(element, _s)) return element;
    }
    return null;
  }
private @Nullable Object findFirstElement(String s)