private function createParameters($pipe, $request, $stack, $isString = false)
    {
        if ($isString) {
            list($name, $parameters) = $this->parsePipeString($pipe);

            if (!is_object($this->container)) {
                throw new PipelineException(sprintf('%s expects container instance', get_class($this)));
            }

            $pipe = ($this->container->has($name)) ? $this->container->get($name) : $this->container->make($name);
            $parameters = array_merge([$request, $stack], $parameters);
        } else {
            $parameters = [$request, $stack];
        }

        return [[$pipe, $this->method], $parameters];
    }