anchor.diff:  	@ResponseBody
   	public DeferredResult<String> quotes() {
   		DeferredResult<String> deferredResult = new DeferredResult<String>();
  -		// Save the deferredResult in in-memory queue ...
  +		// Save the deferredResult somewhere..
   		return deferredResult;
   	}
   
  
positive.code: 
  ----
  
  If using Servlet 3, Java based configuration, e.g. via `WebApplicationInitializer`,
  you'll also need to set the "asyncSupported" flag as well as the ASYNC dispatcher type
  just like with `web.xml`. To simplify all this configuration, consider extending
  `AbstractDispatcherServletInitializer` or
  `AbstractAnnotationConfigDispatcherServletInitializer`, which automatically set those
  options and make it very easy to register `Filter` instances.
  
  [[mvc-ann-async-configuration-spring-mvc]]
  ===== Spring MVC Async Config
  The MVC Java config and the MVC namespace both provide options for configuring async
  request processing. `WebMvcConfigurer` has the method `configureAsyncSupport` while
  <mvc:annotation-driven> has an <async-support> sub-element.
  
  Those allow you to configure the default timeout value to use for async requests, which
  if not set depends on the underlying Servlet container (e.g. 10 seconds on Tomcat). You
  
negative.code: 	</web-app>
  ----
  
  Asynchronous support must be enabled on the `DispatcherServlet` through the
  `<async-supported>true</async-supported>` web.xml sub-element. Additionally
  any `Filter` that participates in asyncrequest processing must be configured
  to support the ASYNC dispatcher type. It should be safe to enable the ASYNC
  dispatcher type for all filters provided with the Spring Framework since they
  usually extend `OncePerRequestFilter` and that has runtime checks for whether
  the filter needs to be involved in async dispatches or not.
  
  Below is some example web.xml configuration:
  
  [source,xml,indent=0]
  [subs="verbatim,quotes"]
  