@Override
        public void process(DocumentPut put) {
            super.process(put);
            if (put.getId().toString().equals("id:failing:test::2")) {
                throw new HandledProcessingException("Failed at receiving document test:2");
            }
        }
Tests chaining of some processors, and execution of the processors
on some documents
docproc/src/test/java/com/yahoo/docproc/FailingDocumentProcessingTestCase.java