How can I check for multiples of a product ID with the API? E.g. Code: require_once '....../bootstrap.php'; $user = Am_Di::getInstance()->userTable->findFirstBy(array('login' => $username)); $active_subs = $user->getActiveProductIds(); print_r($active_subs); This would show E.g. Array (  => 9  => 39  => 71 ) Whereas the user actually has multiples of product ID 39. Is there a way to get active product ID's, or to check how many multiples a user has of a specific product ID?