public function setMaxPlays($maxPlays)
    {
        if (is_int($maxPlays) && $maxPlays >= 0) {
            $this->maxPlays = $maxPlays;
        } else {
            $msg = "The 'maxPlays' argument must be a positive (>= 0) integer, '" . gettype($maxPlays) . "' given.";
            throw new InvalidArgumentException($msg);
        }
    }