sclass SortedCondensedStrings2 extends CondensedStrings2 {
  *() {}
  
  *(L<S> l) {
    super(sorted(l));
  }
  
  public int indexOf(O o) {
    ret max(-1, Collections.binarySearch(this, o));
  }
  
  public bool contains(O o) {
    ret indexOf(o) >= 0;
  }
}