@Override public boolean addAll(Collection<? extends E> c){
  Iterator<? extends E> i=c.iterator();
  boolean changed=false;
  while (i.hasNext()) {
    boolean ret=add(i.next());
    if (!changed) {
      changed=ret;
    }
  }
  return changed;
}

@ Override public boolean addAll ( Collection < ? extends E > c ) { Iterator < ? extends E > i = c . iterator ( ) ; boolean changed = false ; while ( i . hasNext ( ) ) { boolean ret = add ( i . next ( ) ) ; if ( ! changed ) { changed = ret ; } } return changed ; }
add all of the elements in the given collection to this list .
