boolean closeInSize(long size1, long size2, long delta) {
    long lower = size1 - delta;
    long upper = size1 + delta;
    return lower <= size2 && size2 <= upper;
  }
Computes if {@code size2} is within {@code delta} of {@code size1}, inclusive.
hbase-server/src/test/java/org/apache/hadoop/hbase/quotas/TestSnapshotQuotaObserverChore.java