public void SetUp() {
            lst = new List<IWritable>();
            IElementHandler elemH = new CustomElementHandler();

            p = new ElementHandlerPipeline(elemH, null);
            po = new ProcessObject();
            writable = new WritableElement(new Chunk("aaaaa"));
            po.Add(writable);
            context = new WorkerContextImpl();
            p.Init(context);
        }