public function withHandler($handler): self
    {
        return tap($this, function ($request) use ($handler) {
            return $this->handler = $handler;
        });
    }
public function withHandler($handler): self
    {
        return tap($this, function ($request) use ($handler) {
            return $this->handler = $handler;
        });
    }
public function withHandler ( $ handler ) : self { return tap ( $ this , function ( $ request ) use ( $ handler ) { return $ this -> handler = $ handler ; } ) ; }
Handle requests with the given class.

@param mixed $handler

@return \BrianFaust\Http\PendingHttpRequest
Handle requests with the given class .