  @Test
  void should_reject_request_with_invalid_accept() {

    DiagramHandler diagramHandler = new DiagramHandler(mockDiagramService(Lists.newArrayList(FileFormat.SVG), null));
    MockDiagramRequest mockDiagramRequest = new MockDiagramRequest();
    mockDiagramRequest.setMethod(HttpMethod.POST);
    mockDiagramRequest.addAccept("text/html");
    mockDiagramRequest.setContentType("text/plain");
    mockDiagramRequest.setBodyAsString("Bob -> Alice : hello");
    RoutingContext routingContext = mockDiagramRequest.getRoutingContext();
    diagramHandler.createPost("plantuml").handle(routingContext);
    verify(routingContext).fail(any(UnsupportedMimeTypeException.class)); // diagram handles svg only
  }