This method, SplObjectStorage::getInfo() does NOT exist on PHP 5.2.13. However, PHP 5.3.2 and above does have it. To find out yourself, use this snippet. $> php -r "print_r(get_class_methods(new SplObjectStorage()));"Results for PHP 5.2.13====Array( [0] => attach [1] => detach [2] => contains [3] => count [4] => rewind [5] => valid [6] => key [7] => current [8] => next [9] => unserialize [10] => serialize)Results for PHP 5.3.2=====Array( [0] => attach [1] => detach [2] => contains [3] => addAll [4] => removeAll [5] => getInfo [6] => setInfo [7] => count [8] => rewind [9] => valid [10] => key [11] => current [12] => next [13] => unserialize [14] => serialize [15] => offsetExists [16] => offsetSet [17] => offsetUnset [18] => offsetGet)