@Override
        public Progress process(Processing processing) {
            List<DocumentOperation> docs = processing.getDocumentOperations();
            assertEquals(1, docs.size());
            DocumentId id = docs.get(0).getId();
            if ("id:ns:baz::transform".equals(id.toString())) {
                docs.clear();
                docs.add(new DocumentPut(type, "id:ns:baz::appended"));
            } else if ("id:ns:baz::append".equals(id.toString())) {
                docs.add(new DocumentPut(type, "id:ns:baz::appended"));
            } else if ("id:ns:baz::append_same".equals(id.toString())) {
                docs.add(new DocumentPut(type, "id:ns:baz::append_same"));

            }
            return Progress.DONE;
        }
@author <a href="mailto:einarmr@yahoo-inc.com">Einar M R Rosenvinge</a>
docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerForkTestCase.java