@Override
    public List<Cell> get(Get get, boolean withCoprocessor) throws IOException {
      List<Cell> cells = super.get(get, withCoprocessor);
      sleep(600);
      return cells;
    }
An override of HRegion to allow sleep after get(), waiting for the release of DBB
hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestCheckAndMutateWithByteBuff.java