@Test
  public void testOffHeapBucketCacheConfig() {
    this.conf.set(HConstants.BUCKET_CACHE_IOENGINE_KEY, "offheap");
    doBucketCacheConfigTest();
  }
Assert that the caches are deployed with CombinedBlockCache and of the appropriate sizes.
hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestCacheConfig.java