@Override
  public void stop() {
    LlapIoImpl.LOG.debug("Encoded reader is being stopped");
    isStopped.set(true);
  }
Data from cache currently being processed. We store it here so that we could decref
it in case of failures. We remove each slice from the data after it has been sent to
the consumer, at which point the consumer is responsible for it.
llap-server/src/java/org/apache/hadoop/hive/llap/io/encoded/SerDeEncodedDataReader.java