VersionUserType::getActivityUserId

static function getActivityUserId()
{
	global $USER;
	if($USER && $USER instanceof CUser)
	{
		$userId = $USER->getId();
		if(is_numeric($userId) && ((int)$userId > 0))
		{
			return $userId;
		}
	}

	return SystemUser::SYSTEM_USER_ID;
}