public function newAppendNotify(User $fromUser, Topic $topic, Append $append)
{
$users = $topic->replies()->with('user')->get()->lists('user');
// Notify commented user
Notification::batchNotify('comment_append', $fromUser, $this->removeDuplication($users), $topic, null, $append->content);
// Notify attented users
Notification::batchNotify('attention_append', $fromUser, $this->removeDuplication($topic->attentedBy), $topic, null, $append->content);
}
