public int hashCode(){
  int hash=mask;
  if (rangeSet != null) {
    hash&=CONTEXTUAL_MASK;
    hash^=rangeSet.hashCode();
  }
  return hash;
}

public int hashCode ( ) { int hash = mask ; if ( rangeSet != null ) { hash &= CONTEXTUAL_MASK ; hash ^= rangeSet . hashCode ( ) ; } return hash ; }
returns a hash code for this shaper .
