private void verifySavedBytesCount(long logSegmentCountBeforeCompaction, long alreadySavedBytes) {
    long expectedSavedBytes =
        state.log.getSegmentCapacity() * (logSegmentCountBeforeCompaction - state.index.getLogSegmentCount());
    long savedBytesReported = alreadySavedBytes + metricRegistry.getCounters()
        .get(MetricRegistry.name(BlobStoreCompactor.class, "CompactionBytesReclaimedCount"))
        .getCount();
    assertEquals("Saved bytes reported not equal to expected", expectedSavedBytes, savedBytesReported);
  }
Verifies that the metric reporting the number of bytes saved after compaction is correct.
@param logSegmentCountBeforeCompaction the number of log segments in the {@link Log} before compaction.
@param alreadySavedBytes the number of bytes that have already been saved but won't show up in the metric registry
(because it may have been re-inited).
ambry-store/src/test/java/com/github/ambry/store/BlobStoreCompactorTest.java