public function approve($model)
    {
        $approvedAtLeastOne = false;

        if ($model->friends->count()) {
            foreach ($model->friends as $friend) {
                if ((int) $friend->getKey() === (int) $this->getKey()) {
                    $friend->pivot->approved_at = new \Carbon\Carbon;
                    $friend->pivot->save();
                    $this->resetFriends();

                    $approvedAtLeastOne = true;
                }
            }
        }

        return $approvedAtLeastOne;
    }