public function setRequestMode($mode)
    {
        if (!in_array($mode, ['real', 'simu'])) {
            $message = sprintf(
              'The request mode %s is not supported, real or simu expected!',
              $mode
            );
            throw new \InvalidArgumentException($message, 500);
        }
        $this->params['request_mode'] = $mode;
        return $this;
    }