title: Error Call to a member function delay() on null when call in $user->notify($natifictionclass)->delay()
body: <p>Call to a member function delay() on null</p>
  
  <p>I am getting above when i am calling notify method with dealy.</p>
  
  <p>Notication class i am geting.in job table data is store but  i am getting  error in call to member function delay on null. can one  help me in that.</p>
  
  <pre><code>use Illuminate\Database\Eloquent\Model;
  use Illuminate\Notifications\Notifiable;
  
  class User extends Model
  {
      //
      use Notifiable;
      /**
       * The database table used by the model.
       *
       * @var string
       */
      protected $table = 'user';
      /**
       .....
  }
  </code></pre>
  
  <p>notification class</p>
  
  <pre><code>    namespace App\Notifications;
  
      use App\Channels\PushChannel;
      use App\Channels\SmsChannel;
      use App\Libraries\Helper;
      use App\Waitlists;
  
      use Illuminate\Bus\Queueable;
      use Illuminate\Notifications\Notification;
      use Illuminate\Contracts\Queue\ShouldQueue;
      use Illuminate\Contracts\Broadcasting\ShouldBroadcast;
  
      use Illuminate\Queue\SerializesModels;
      use Illuminate\Queue\InteractsWithQueue;
  
      class WaitingPrecall extends Notification implements  ShouldBroadcast
      {
  
      use Queueable;
  
      /**
       * Create a new notification instance.
       *
       * @return void
       */
      public $message;
      public $phone;
  
  
      public $deviceGuests;
  
      public function _construct()
      {
  
      }
  
      /**
       * Get the notification's delivery channels.
       *
       * @param  mixed  $notifiable
       * @return array
       */
      public function via($notifiable)
      {
          return $this-&gt;sendtype==1?[PushChannel::class]: [PushChannel::class,SmsChannel::class];
      }
  
      /**
       * Get the mail representation of the notification.
       *
       * @param  mixed  $notifiable
       * @return \Illuminate\Notifications\Messages\MailMessage
       */
  
      public function toSms($notifiable)
      {
           $data=Helper::send_message($this-&gt;smstext,$this-&gt;phone);
  
           return $data;
      }
  }
  </code></pre>
  
  <p>function call for</p>
  
  <pre><code>$waitPreCall=new WaitingPrecall();
  
  ....
  ....
  
  $guest=User::find($waitDataNew-&gt;user-&gt;gust_id);
  
   $guest-&gt;notify($waitPreCall)-&gt;delay($when);//here i am getting error
  </code></pre>