code: private function curlOptions()
      {
          $options = [
              // CURLOPT_VERBOSE => true,
              CURLOPT_CONNECTTIMEOUT => $this->connectionTimeout,
              CURLOPT_HEADER => true,
              CURLOPT_RETURNTRANSFER => true,
              CURLOPT_SSL_VERIFYHOST => 2,
              CURLOPT_SSL_VERIFYPEER => true,
              CURLOPT_TIMEOUT => $this->timeout,
              CURLOPT_USERAGENT => $this->userAgent,
          ];
  
          if ($this->useCAFile()) {
              $options[CURLOPT_CAINFO] = __DIR__ . DIRECTORY_SEPARATOR . 'cacert.pem';
          }
  
          if ($this->gzipEncoding) {
              $options[CURLOPT_ENCODING] = 'gzip';
          }
  
          if (!empty($this->proxy)) {
              $options[CURLOPT_PROXY] = $this->proxy['CURLOPT_PROXY'];
              $options[CURLOPT_PROXYUSERPWD] = $this->proxy['CURLOPT_PROXYUSERPWD'];
              $options[CURLOPT_PROXYPORT] = $this->proxy['CURLOPT_PROXYPORT'];
              $options[CURLOPT_PROXYAUTH] = CURLAUTH_BASIC;
              $options[CURLOPT_PROXYTYPE] = CURLPROXY_HTTP;
          }
  
          return $options;
      }
docs: Set Curl options.
  
  @return array