@After
  public void tearDown() throws IOException {
    region.close(true);
    hfileCleanerPool.shutdownNow();
    logCleanerPool.shutdownNow();
    choreService.shutdown();
    htu.cleanupTestDir();
  }
Creates a new MasterRegion using an existing {@code htu} on this class.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/region/MasterRegionTestBase.java