_domain.getTransformerRegistry().addTransformer(new StreamTransformer());
ServiceReference service = _domain.createInOnlyService(new QName("StreamTest"), provider);
InputStream contentAsStream = new ByteArrayInputStream(contentAsString.getBytes());
Exchange ex = service.createExchange();
Message msg = ex.createMessage();
msg.setContent(contentAsStream);
ex.send(msg);
Message rcvdMsg = provider.getMessages().poll().getMessage();
Assert.assertTrue(rcvdMsg.getContent(InputStream.class).available() > 0);