/**
* Get all the results matching one of the given types
* @param array ...$types
* @return ItemPosition[]
*/
public function getResultsByType($types)
{
$types = func_get_args();
$items = new ResultSet();
foreach ($this->items as $item) {
if (call_user_func_array([$item, 'is'], $types)) {
$items->addItem($item);
}
}
return $items;
}