source: class SensorDataTest {
  
    @Test
    void testAverage(Vertx vertx, VertxTestContext ctx) {
  
target:     EventBus bus = vertx.eventBus();
      vertx.deployVerticle(new SensorData(), ctx.succeeding(id -> {
        bus.publish("sensor.updates", new JsonObject()
          .put("id", "a").put("temp", 20.0d));
        bus.publish("sensor.updates", new JsonObject()
          .put("id", "b").put("temp", 22.0d));
        bus.request("sensor.average", "", ctx.succeeding(reply -> ctx.verify(() -> {
          JsonObject json = (JsonObject) reply.body();
          assertEquals(21.0d, (double) json.getDouble("average"));
          ctx.completeNow();
        })));
      }));
    }
  
  }