@Test public void testHandleRequestIssues() { TestEndpoint endp = new TestEndpoint(); TestMessageConsumer consumer = new TestMessageConsumer(); RemoteEndpoint endpoint = new RemoteEndpoint(consumer, endp); endpoint.handle(init(new RequestMessage(), it -> { it.setId("1"); it.setMethod("foo"); it.setParams("myparam"); }), Collections.singletonList(new MessageIssue("bar"))); ResponseMessage responseMessage = (ResponseMessage) consumer.messages.get(0); assertNotNull(responseMessage.getError()); assertEquals("bar", responseMessage.getError().getMessage()); }