public void print(PrintWriter out){
  for (  S key : keys) {
    print(out,key,map.get(key));
  }
  out.flush();
}

public void print ( PrintWriter out ) { for ( S key : keys ) { print ( out , key , map . get ( key ) ) ; } out . flush ( ) ; }
output each entry in the hashmap on a line separated by a tab .
