code: public function request($method, $url, $options = [])
      {
          $method = strtoupper($method);
  
          $options = array_merge(self::$defaults, ['headers' => $this->headers], $options);
  
          return $this->getClient()->request($method, $url, $options);
      }
docs: Send A Http Request For GuzzleHttp Http Client
  
  @param  string $method
  @param  string $url
  @param  array  $options
  
  @return \Psr\Http\Message\ResponseInterface