code: public function request($url)
      {
          $ch = curl_init();
  
          curl_setopt($ch, CURLOPT_URL, $url);
          curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
          curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $this->timeout);
  
          $response = curl_exec($ch);
  
          curl_close($ch);
  
          if ($response === false) {
              throw new \RuntimeException('Connection timeout.');
          }
  
          return $response;
      }
docs: Make a HTTP request.
  
  @param string $url
  @return string Response body.
  @throws \RuntimeException