@Override
    public Optional<RegionObserver> getRegionObserver() {
      return Optional.of(this);
    }
Add cell tags to delete mutations, run export and import tool and verify that tags are present
in import table also.
@throws Throwable throws Throwable.
hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TestImportExport.java