private function handleMissingRequiredParameters()
    {
        $leftover = count($this->requiredParams);

        if (0 < $leftover) {
            if (1 == $leftover) {
                $msg = 'The required parameter \'%s\' is missing';
            } else {
                $msg = 'The required parameters \'%s\' are missing';
            }

            throw new \Exception(sprintf($msg, implode('\', \'', $this->requiredParams)));
        }
    }