$iso
is now required. As a result, the order of method arguments has changed.
\Checkdomain\Holiday\Util::isHoliday($iso, $date = 'now', $state = null);
\Checkdomain\Holiday\Util::getHoliday($iso, $date = 'now', $state = null);
instead of
\Checkdomain\Holiday\Util::isHoliday($date = 'now', $iso = null, $state = null);
\Checkdomain\Holiday\Util::getHoliday($date = 'now', $iso = null, $state = null);