for DateTieredCompactionStrategy, TIMESTAMP_RESOLUTION_KEY sets wrong msxSSTableAge value if RESOLUTION is other than MILLISECONDS

I was trying to set 'timestamp_resolution' to MINUTES/HOURS/DAYS. it turned out maxSSTableAge was set as wrong value. In the code,

    public DateTieredCompactionStrategyOptions(Map<String, String> options)
    {
        String optionValue = options.get(TIMESTAMP_RESOLUTION_KEY);
        TimeUnit timestampResolution = optionValue == null ? DEFAULT_TIMESTAMP_RESOLUTION : TimeUnit.valueOf(optionValue);
        optionValue = options.get(MAX_SSTABLE_AGE_KEY);
        double fractionalDays = optionValue == null ? DEFAULT_MAX_SSTABLE_AGE_DAYS : Double.parseDouble(optionValue);
        maxSSTableAge = Math.round(fractionalDays * timestampResolution.convert(1, TimeUnit.DAYS));
 ...   }

maxSSTableAge will be set as the value in "timestamp_resolution" unit, such as , with the following settings,
'timestamp_resolution':'HOURS',
'max_sstable_age_days':'7',
'base_time_seconds':'3600'
and I get:
maxSSTableAge=168, baseTime=1

while in the following routine, it expect maxSSTableAge as milliseconds
static Iterable<SSTableReader> filterOldSSTables(List<SSTableReader> sstables, long maxSSTableAge, long now)