PayWithAmazon\IpnHandler::__set PHP Method

    public function __set($name, $value)
    {
        if (array_key_exists(strtolower($name), $this->ipnConfig)) {
            $this->ipnConfig[$name] = $value;
        } else {
            throw new \Exception("Key " . $name . " is not part of the configuration", 1);
        }
    }