/**
  * @param array $params
  * @return \App\DataAccess\Eloquent\User
  */
 public function registerUser(array $params)
 {
     $user = $this->user->save($params);
     $this->mailer->send('emails.register', ['user' => $user], function ($m) use($user) {
         $m->sender('*****@*****.**', 'Laravel リファレンス')->to($user->email, $user->name)->subject('ユーザー登録が完了しました');
     });
 }