@Streaming(false)
        @Get("/serverSentEvent")
        @ResponseConverter(ServerSentEventResponseConverterFunction.class)
        public ServerSentEvent serverSentEvent() {
            return ServerSentEvent.ofData("serverSentEvent");
        }
A mock service for testing {@link ServerSentEventResponseConverterFunction}.
core/src/test/java/com/linecorp/armeria/internal/server/annotation/ResponseStreamingTest.java