public function getPendingFriends()
 {
     $user_id = $this->user_id;
     $query = "select * from user_info t1 where user_id in (select friend_id as user_id from friend_info where user_id=" . $user_id . " and friend_status='pending' and friend_id<>" . $user_id . ")";
     $records = $this->db->query($query);
     return User_info::instantiate($records);
 }