public function attach($provider_name) {
        $response = null;


        $profile = null;
        $identifier = $this->auth($provider_name, $profile);
        if(!$this->checkRegistered($provider_name, $identifier)) {

            $id = Auth::user()->getAuthIdentifier();

            $login = $this->login_repository->create();
            $login->setProvider($provider_name);
            $login->setIdentifier($identifier);
            $login->setUser($id);

            if($this->login_repository->save($login)) {
	            $providers = SocialAuth::getConnectedProviders();
	            $socialProfile = $providers[$provider_name]->getProfile();
	            Event::fire('social-auth.attach', ['user' => Auth::user(),  'provider' => $provider_name, 'profile' => $socialProfile]);
                $response = Redirect::back()->with(['message' => trans('social-auth::user.account attach success',
                    ['provider' => $provider_name, 'accountname' => $socialProfile->getDisplayName()])]);
            } else {
                $response = Redirect::back()->withErrors(['message' => trans('social-auth::user.account attach fail', ['accoutnname' => $profile->displayName])]);
            }

        } else {
            $response = Redirect::back()->withErrors(['message' => trans('social-auth::user.account already registered', ['accountname' => $profile->displayName]) ]);
        }

        return $response;
    }