我有这个方法:
$user=Sentinel::findById($user->id);
$reminder=Reminder::exists($user)? : Reminder::create($user);
$this->sendEmail($user, $reminder->code);
return redirect()->back()->with(['success'=>'reset code sent']);
但是它显示一个错误,Undefined type 'App\Http\Controllers\Security\Sentinel'
有谁知道如何消除这个错误?