private function configure($config = [])
    {
        $this->config = $config;

        $this->configureVariable('ssl');
        $this->configureVariable('ssl_method');
        $this->configureVariable('ssl_name');
        $this->configureVariable('ssl_verify_sign');
        $this->configureVariable('ssl_verify_peer');
        $this->configureVariable('ssl_verify_depth');
    }