GatewayController.php

<?php

class GatewayController extends Controller
{
    /**
     * @param Request $request
     * @param RestClient $client
     * @return Response
     */
    public function get(Request $request, RestClient $client)
    {
        $parametersJar = $request->getRouteParams();
        $output = $this->actions->reduce(function($carry, $batch) use (&$parametersJar, $client) {
            $responses = $client->asyncRequest($batch, $parametersJar);
            $parametersJar = array_merge($parametersJar, $responses->exportParameters());
            return array_merge($carry, $responses->getResponses()->toArray());
        }, []);
        return $this->presenter->format($this->rearrangeKeys($output), 200);
    }
}