Core/src/RequestWrapper.php
private function buildDefaultAsyncHandler()
    {
        $isGuzzleHandler = $this->httpHandler instanceof Guzzle6HttpHandler
            || $this->httpHandler instanceof Guzzle5HttpHandler;

        return $isGuzzleHandler
            ? [$this->httpHandler, 'async']
            : [HttpHandlerFactory::build(), 'async'];
    }
private function buildDefaultAsyncHandler()
    {
        $isGuzzleHandler = $this->httpHandler instanceof Guzzle6HttpHandler
            || $this->httpHandler instanceof Guzzle5HttpHandler;

        return $isGuzzleHandler
            ? [$this->httpHandler, 'async']
            : [HttpHandlerFactory::build(), 'async'];
    }
private function buildDefaultAsyncHandler ( ) { $ isGuzzleHandler = $ this -> httpHandler instanceof Guzzle6HttpHandler || $ this -> httpHandler instanceof Guzzle5HttpHandler ; return $ isGuzzleHandler ? [ $ this -> httpHandler , 'async' ] : [ HttpHandlerFactory :: build ( ) , 'async' ] ; }
Builds the default async HTTP handler.

@return callable
Builds the default async HTTP handler .