code: public ItemReader<Chunk<T>> getOrCreateReader()
     {
        Node node = childNode.getOrCreate("reader");
        ItemReader<Chunk<T>> reader = new ItemReaderImpl<Chunk<T>>(this, "reader", childNode, node);
        return reader;
     }
docs: If not already created, a new <code>reader</code> element with the given value will be created.
  Otherwise, the existing <code>reader</code> element will be returned.
  @return  a new or existing instance of <code>ItemReader<Chunk<T>></code>