@Override public int hashCode(){
  int result=1;
  Iterator<?> it=iterator();
  while (it.hasNext()) {
    Object object=it.next();
    result=(31 * result) + (object == null ? 0 : object.hashCode());
  }
  return result;
}

@ Override public int hashCode ( ) { int result = 1 ; Iterator < ? > it = iterator ( ) ; while ( it . hasNext ( ) ) { Object object = it . next ( ) ; result = ( 31 * result ) + ( object == null ? 0 : object . hashCode ( ) ) ; } return result ; }
returns the hash code of this list . the hash code is calculated by taking each element ' s hashcode into account .
