public function getAuthentication( ThreeDSecure\Authentications $authentications )
    {
        $authentications->checkRequiredFields();
        $request = new Request(array(
            'method' => Request::GET,
            'uri' => $this->prepareURI("/authentications/" . $authentications->id),
            'body' => $authentications
        ));
        $response = $this->client->processRequest($request);
        return new ThreeDSecure\Authentications($response);
    }