CListPermissions::_lists_check

protected function _lists_check($USER, $iblock_type_id, $iblock_id)
{
	$iblock_check = CListPermissions::_iblock_check($iblock_type_id, $iblock_id);
	if($iblock_check < 0)
		return $iblock_check;

	$arListsPerm = CLists::GetPermission($iblock_type_id);
	if(!$arListsPerm)
	{
		return CListPermissions::ACCESS_DENIED;
	}

	$arUSER_GROUPS = $USER->GetUserGroupArray();
	if(count(array_intersect($arListsPerm, $arUSER_GROUPS)) > 0)
		return CListPermissions::IS_ADMIN;

	return CIBlock::GetPermission($iblock_id);
}