private function doRequest($path, $headers = [])
    {
        if (!$this->isAvailable()) {
            throw new NotAvailableException('Service not available.');
        }

        if ($this->loadBalance !== null) {
            $uri = $this->loadBalance->getUri($this->serviceName);
            $this->zendClient->setUri($uri);
        }
        if ($this->appendPath && strlen($path) > 0 && $this->zendClient->getUri()->getPath() != '/') {
            $path = $this->zendClient->getUri()->getPath() . $path;
        }
        $this->zendClient->getUri()->setPath($path);

        $this->zendClient->getRequest()->getHeaders()->addHeaders($headers);

        if (!$this->zendClient->getRequest()->getHeaders()->has('X-Request-Id')) {
            $this->addRequestId();
        }

        $this->addRequestName($this->serviceName);

        $this->getEventManager()->trigger('request.pre', $this);

        $this->responseTime = 0;

        try {
            $requestTime = microtime(true);

            $zendHttpResponse = $this->zendClient->send();

            $this->responseTime = (float) sprintf('%.2f', (microtime(true) - $requestTime) * 1000);

            $this->addRequestTime($this->responseTime);

            $response = new Response($this->zendClient, $zendHttpResponse, $this->depth);
            $this->reportSuccess();
        } catch (RuntimeException $ex) {
            $this->reportFailure();
            $this->getEventManager()->trigger('request.fail', $this, $ex);
            throw new RuntimeException($ex->getMessage(), $ex->getCode(), $ex);
        } catch (\Exception $ex) {
            $this->reportFailure();
            $this->getEventManager()->trigger('request.fail', $this, $ex);
            throw new RuntimeException($ex->getMessage(), 500, $ex);
        }

        $this->getEventManager()->trigger('request.post', $this);

        $content = $response->getContent();

        return $content;
    }