public function usingService($serviceName)
    {
        // Check if service exists first.
        if (! config()->has('watson-bridge.services.'.$serviceName)) {
            throw new WatsonBridgeException('Unknown service "'.$serviceName.'" try adding it to the list of services in watson-bridge config.');
        }

        // Get service endpoint.
        $serviceUrl = config('watson-bridge.services.'.$serviceName);

        // Reset Client.
        $this->setClient(rtrim($this->endpoint, '/').'/'.ltrim($serviceUrl, '/'));

        return $this;
    }