@Test
  public void testWarmupAndClose() throws IOException {
    HRegionServer rs = TEST_UTIL.getMiniHBaseCluster().getRegionServer(0);
    HRegion region = TEST_UTIL.getMiniHBaseCluster().getRegions(TABLENAME).get(0);
    RegionInfo info = region.getRegionInfo();

    TableDescriptor htd = table.getDescriptor();
    HRegion warmedUpRegion =
      warmupHRegion(info, htd, rs.getWAL(info), rs.getConfiguration(), rs, null);
    assertTrue(warmedUpRegion.isClosed());
  }
Basic client side validation of HBASE-4536
hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestWarmupRegion.java