/**
* Evaluate the contao 2 sorting flag into grouping length.
*
* @param ListingConfigInterface|PropertyInterface $config The property to evaluate the flag for.
*
* @param int $flag The flag to be evaluated.
*
* @return void
*/
protected function evalFlagGroupingLength($config, $flag)
{
if ($flag == 1 || $flag == 2) {
$config->setGroupingLength(1);
} elseif ($flag == 3 || $flag == 4) {
$config->setGroupingLength(2);
}
}
