code: protected static function buildHttpClient05(
          LoopInterface $loop,
          $connector = null
      ) {
          // build a connector with given DnsResolver if provided (old deprecated behavior)
          if ($connector instanceof DnsResolver) {
              @trigger_error(
                  sprintf(
                      'Passing a %s to buildHttpClient is deprecated since version 2.1.0 and will be removed in 3.0. If you need no specific behaviour, omit the $dns argument, otherwise pass a %s',
                      DnsResolver::class,
                      ConnectorInterface::class
                  ),
                  E_USER_DEPRECATED
              );
              $connector = static::buildConnector($loop, $connector);
          }
  
          // validate connector instance for proper error reporting
          if (null !== $connector && !$connector instanceof ConnectorInterface) {
              throw new \InvalidArgumentException(
                  '$connector must be an instance of DnsResolver or ConnectorInterface'
              );
          }
  
          return new HttpClient($loop, $connector);
      }
docs: Builds a React Http client v0.5 style.
  
  @param LoopInterface                       $loop
  @param DnsResolver|ConnectorInterface|null $connector
  
  @return HttpClient