code: protected function parseHeaderLine($header_line)
      {
          if (preg_match('/HTTP\/(\d+\.\d+)\s+(\d+)/i', $header_line, $matches)) {
              $this->http_version  = $matches[1];
              $this->response_code = $matches[2];
          }
          if (preg_match('/Content-type:\s*(.*)/i', $header_line, $matches)) {
              $this->mime_type = trim($matches[1]);
          }
          if (preg_match('/Location:\s*(.*)/i', $header_line, $matches)) {
              $this->location = trim($matches[1]);
          }
          if (preg_match('/Set-cookie:(.*)/i', $header_line, $matches)) {
              $this->cookies[] = $this->parseCookie($matches[1]);
          }
          if (preg_match('/WWW-Authenticate:\s+(\S+)\s+realm=\"(.*?)\"/i', $header_line, $matches)) {
              $this->authentication = $matches[1];
              $this->realm          = trim($matches[2]);
          }
      }
docs: Called on each header line to accumulate the held data within the class.
  
  @param string $header_line        One line of header.