php7 memcached getMulti

Seems like the signature changed

Warning: Memcached::getMulti() expects at most 2 parameters, 3 given

code
$results = $mc->getMulti($full_keys, $null, Memcached::GET_PRESERVE_ORDER);

Seems like it was allowed and has not been updated here:

https://github.com/php-memcached-dev/php-memcached/blob/php7/memcached-api.php#L196

But not according to the code, it has been removed (cas_tokens)

https://github.com/php-memcached-dev/php-memcached/blob/php7/php_memcached.c#L3732