@Override
    public boolean postScannerNext(ObserverContext<? extends RegionCoprocessorEnvironment> e,
      InternalScanner s, List<Result> results, int limit, boolean hasMore) throws IOException {
      if (checkTagPresence) {
        if (results.size() > 0) {
          // Check tag presence in the 1st cell in 1st Result
          Result result = results.get(0);
          ExtendedCellScanner cellScanner = result.cellScanner();
          if (cellScanner.advance()) {
            ExtendedCell cell = cellScanner.current();
            tags = PrivateCellUtil.getTags(cell);
          }
        }
      }
      return hasMore;
    }
Test that we can do reverse scans when writing tags and using DataBlockEncoding. Fails with an
exception for PREFIX, DIFF, and FAST_DIFF
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestTags.java