private function randomPassword()
    {
        $alphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
        $pass = []; // remember to declare $pass as an array
        $alphaLength = strlen($alphabet) - 1; // put the length -1 in cache