@Get("/jsonFuture")
        @Streaming(false)
        public CompletableFuture<JsonNode> jsonFuture() {
            return UnmodifiableFuture.completedFuture(new TextNode("jsonFuture"));
        }
A mock service for testing {@link JacksonResponseConverterFunction}.
core/src/test/java/com/linecorp/armeria/internal/server/annotation/ResponseStreamingTest.java