public function getConfParam($param, $default = null)
    {
        if (isset($this->params[$param])) {
            return $this->paymentHandler->formatConfigParam($param, $this->params[$param]);
        } elseif (isset($default)) {
            return $default;
        } else {
            throw new Exception("Configuration parameter '$param' not set for adapter '" . $this->name . "'");
        }
    }