/**
  * Refreshes channel users data.
  *
  * @return null
  */
 public function refreshChannelUsersData()
 {
     $this->channelUsersDAO->deleteOlderByLastActivityTime(self::USERS_PRESENCE_TIME_FRAME);
     $this->channelUsersDAO->updateActiveForOlderByLastActivityTime(false, self::USERS_ACTIVITY_TIME_FRAME);
 }