code: public final boolean overlaps(HString other) {
        if (other == null) {
           return false;
        }
        return (document() != null && other.document() != null) &&
                  (document() == other.document()) &&
                  super.overlaps(other);
     }
docs: Checks if this HString overlaps with the given other.
  
  @param other The other HString
  @return True of this one overlaps with the given other.