### Question:
DiagnosticController { public Response thread(Request request) { accessControl.validate(request.clientIP()); return Response.text(Diagnostic.thread()); }  Response vm(Request request); Response thread(Request request); Response heap(Request request);  }### Answer:
@Test void thread() { Response response = controller.thread(request); assertThat(response.contentType()).get().isEqualTo(ContentType.TEXT_PLAIN); }