public static int hash(int hash,double item){
  long l=Double.doubleToLongBits(item);
  return seed * prime + (int)(l ^ (l >>> 32));
}

public static int hash ( int hash , double item ) { long l = Double . doubleToLongBits ( item ) ; return seed * prime + ( int ) ( l ^ ( l > > > 32 ) ) ; }
add a double value to a given hash .
