@Parameters
  public static Collection<Object[]> getParameters() throws IOException {
    List<Object[]> params = new ArrayList<>();
    for (BlockCache blockCache : getBlockCaches()) {
      for (CacheOnWriteType cowType : CacheOnWriteType.values()) {
        for (Compression.Algorithm compress : HBaseCommonTestingUtil.COMPRESSION_ALGORITHMS) {
          for (boolean cacheCompressedData : new boolean[] { false, true }) {
            params.add(new Object[] { cowType, compress, cacheCompressedData, blockCache });
          }
        }
      }
    }
    return params;
  }
The number of valid key types possible in a store file
hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestCacheOnWrite.java