public function conversationsWithNewMessages()
 {
     $conversationsWithNewMessages = [];
     $participants = \Andheiberg\Messenger\Models\Participant::where('user_id', $this->id)->lists('last_read', 'conversation_id');
     if ($participants) {
         $conversations = \Andheiberg\Messenger\Models\Conversation::whereIn('id', array_keys($participants))->get();
         foreach ($conversations as $conversation) {
             if ($conversation->updated_at > $participants[$conversation->id]) {
                 $conversationsWithNewMessages[] = $conversation->id;
             }
         }
     }
     return $conversationsWithNewMessages;
 }