public static function getCascadeFactors()
    {
        return static::$cascadeFactors ?: [
            'milliseconds' => [Carbon::MICROSECONDS_PER_MILLISECOND, 'microseconds'],
            'seconds' => [Carbon::MILLISECONDS_PER_SECOND, 'milliseconds'],
            'minutes' => [Carbon::SECONDS_PER_MINUTE, 'seconds'],
            'hours' => [Carbon::MINUTES_PER_HOUR, 'minutes'],
            'dayz' => [Carbon::HOURS_PER_DAY, 'hours'],
            'months' => [Carbon::DAYS_PER_WEEK * Carbon::WEEKS_PER_MONTH, 'dayz'],
            'years' => [Carbon::MONTHS_PER_YEAR, 'months'],
        ];
    }