Roomify\Bat\Calendar\AbstractCalendar::groupData PHP Method

    public function groupData($data, $length)
    {
        $flipped = array();
        $e = 0;
        $j = 0;
        $old_value = NULL;
        foreach ($data as $datum => $value) {
            $j++;
            if ($j <= $length) {
                // If the value has changed and we are not just starting
                if ($value != $old_value) {
                    $e++;
                    $flipped[$e][$value][$datum] = $datum;
                    $old_value = $value;
                } else {
                    $flipped[$e][$value][$datum] = $datum;
                }
            }
        }
    }