public static function unregisterApp(?string $app = null): void
    {
        self::initialize();
        if ($app === null) {
            $app = '*';
        }
        if (self::isAppRegistered($app)) {
            unset(self::$repositories[$app]);
        }
    }
public static function unregisterApp(?string $app = null): void
    {
        self::initialize();
        if ($app === null) {
            $app = '*';
        }
        if (self::isAppRegistered($app)) {
            unset(self::$repositories[$app]);
        }
    }
public static function unregisterApp ( ? string $ app = null ) : void { self :: initialize ( ) ; if ( $ app === null ) { $ app = '*' ; } if ( self :: isAppRegistered ( $ app ) ) { unset ( self :: $ repositories [ $ app ] ) ; } }
Unregister app.

@param string $app Default null which means default app '*'.
Unregister app .