@Override
  public RegionSizeImpl setSize(long newSize) {
    // Set the new size before advertising that we need to tell the master about it. Worst case
    // we have to wait for the next period to report it.
    size.set(newSize);
    return this;
  }
An object encapsulating a Region's size and whether it's been reported to the master since the
value last changed.
hbase-server/src/main/java/org/apache/hadoop/hbase/quotas/RegionSizeImpl.java