public void add(IPoint pt){
  if (inProgress) {
    throw new ConcurrentModificationException("Can't add point while iterator in progress");
  }
  points.add(pt);
}

public void add ( IPoint pt ) { if ( inProgress ) { throw new ConcurrentModificationException ( "Can't add point while iterator in progress" ) ; } points . add ( pt ) ; }
add point to the result set .
