$cache = new WANObjectCache( [ 'cache' => new HashBagOStuff() ] );
$this->setService( 'MainWANObjectCache', $cache );
$db = wfGetDB( DB_MASTER );
$cache = new WANObjectCache( [ 'cache' => new HashBagOStuff() ] );
$this->setService( 'MainWANObjectCache', $cache );
$db = wfGetDB( DB_MASTER );