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