/**
* @param Request $request
* @return Response
*/
public function callbackAction(Request $request)
{
$requestToken = $request->getSession()->get(self::SESSION_REQUEST_TOKEN);
$request->getSession()->remove(self::SESSION_REQUEST_TOKEN);
$oauth_token = $request->get('oauth_token');
$oauth_verifier = $request->get('oauth_verifier');
$this->validateCallbackTokens($requestToken, $oauth_token, $oauth_verifier);
$accessToken = $this->twitter->getAccessToken($requestToken, $oauth_verifier);
$request->getSession()->set(self::SESSION_ACCESS_TOKEN, $accessToken);
$response = new RedirectResponse($request->getSession()->get(self::SESSION_FORWARD_URI));
$request->getSession()->remove(self::SESSION_FORWARD_URI);
return $response;
}