@Test
  public void testChangingEncoding() throws Exception {
    prepareTest("ChangingEncoding");
    for (boolean onlineChange : new boolean[] { false, true }) {
      for (DataBlockEncoding encoding : ENCODINGS_TO_ITERATE) {
        setEncodingConf(encoding, onlineChange);
        writeSomeNewData();
        verifyAllData();
      }
    }
  }
A zero-based index of the current batch of test data being written
hbase-server/src/test/java/org/apache/hadoop/hbase/io/encoding/TestChangingEncoding.java