@Override
    public String toString() {
      StringBuilder sb = new StringBuilder(32);
      sb.append("SizeSnapshotWithTimestamp={size=").append(size).append("B, ");
      sb.append("time=").append(time).append("}");
      return sb.toString();
    }
Holds the size of a region at the given time, millis since the epoch.
hbase-server/src/main/java/org/apache/hadoop/hbase/quotas/MasterQuotaManager.java