private Map<Long, String> getBoundariesStoragePolicyForMajor(List<Long> boundaries, long now) {
    Map<Long, String> boundariesPolicy = new HashMap<>();
    if (!comConf.isDateTieredStoragePolicyEnable()) {
      return boundariesPolicy;
    }
    for (Long startTs : boundaries) {
      boundariesPolicy.put(startTs, getWindowStoragePolicy(now, startTs));
    }
    return boundariesPolicy;
  }
Returns a list of boundaries for multiple compaction output from minTimestamp to maxTimestamp.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/compactions/DateTieredCompactionPolicy.java