private void fixHoles(CatalogJanitor janitor) throws IOException {
    MetaFixer metaFixer = new MetaFixer(TEST_UTIL.getHBaseCluster().getMaster());
    janitor.scan();
    CatalogJanitorReport report = janitor.getLastReport();
    // Verify total number of holes, 2 in t1, t2, t6 each and one in t3
    assertEquals("Number of holes are not matching", 7, report.getHoles().size());
    metaFixer.fix();
    janitor.scan();
    report = janitor.getLastReport();
    assertEquals("Holes are not fixed", 0, report.getHoles().size());
  }
Take last byte and add one to it.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestCatalogJanitorCluster.java