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