TypeError when trying to use MemcachedHandler for sessions

PHP Code:

    public string $driver = 'CodeIgniter\Session\Handlers\MemcachedHandler'; 


It is recommended that you learn about PHP's namespacing or how to specify a classname.

Oh sorry, my fault.
The import generated by PHPStorm was the wrong one and ( I didn't even think to check it (both extend BaseHandler then no warning was triggered).

... which is probably why it's called MemcachedSessionHandler in Symfony.