@Override
          public long computeAndStoreSnapshotSizes(Collection<String> currentSnapshots)
            throws IOException {
            return tableToSize.get(tn);
          }
Test class for the {@link SnapshotQuotaObserverChore}.
hbase-server/src/test/java/org/apache/hadoop/hbase/quotas/TestSnapshotQuotaObserverChore.java