protected function getDevelopmentEnvironmentContent(Exception $ex, int $statusCode) : string
    {
        ob_start();

        if ($statusCode === 503) {
            require __DIR__ . "/templates/{$this->getRequestFormat()}/MaintenanceMode.php";
        } else {
            require __DIR__ . "/templates/{$this->getRequestFormat()}/DevelopmentException.php";
        }

        return ob_get_clean();
    }