BaseObject::loadUserGroups

static function loadUserGroups($userId)
{
	/* @global CUser $USER */
	global $USER;
	if (!array_key_exists($userId, self::$userGroups))
	{
		if ($USER->getId() == $userId)
		{
			$groups = $USER->getUserGroupArray();
		}
		else
		{
			$groups = BitrixMainUserTable::getUserGroupIds($userId);
			if (empty($groups))
				$groups = array(2);
		}
		self::$userGroups[$userId] = $groups;
	}
	return self::$userGroups[$userId];
}