anchor.diff:  {
     error { ctx, cause, statusCode ->                                        <1>
       val router = ctx.router
  -    log.error("found `{}` error", statusCode.value(), cause)               <2>
  -    ctx.responseStatusCode = statusCode
  -    ctx.send("found `${statusCode.value}` error")                          <3>
  +    router.log.error("found `{}` error", statusCode.value(), cause)        <2>
  +    ctx.responseCode = statusCode
  +    ctx.send("found `${statusCode.value()}` error")                        <3>
     }
   }
   ----
  
positive.code: [source, java, role = "primary"]
  ----
  
  import static io.jooby.Medio.json;
  import static io.jooby.Medio.html;
  
  {
    install(new MyTemplateEngineModule());  <1>
    
    install(new MyJsonModule());            <2>
  
    error((ctx, cause, statusCode) -> {
      Router router = ctx.getRouter();
      router.getLog().error("found `{}` error", statusCode.value(), cause);
      
      MediaType accept = ctx.accepts(json); <3>
      if (json.equals(accept)) {            <4>
        Map error = ...;
        ctx.render(error);
      } else {
        // fallback to html
        Map error = ...;
        ctx.render(new ModelAndView("error.template", error));
      }
    });
  }
  
negative.code:   error((ctx, cause, statusCode) -> {                                      <1>
      Router router = ctx.getRouter();
      router.getLog().error("found `{}` error", statusCode.value(), cause);  <2>
      ctx.setResponseCode(statusCode);
      ctx.send("found `" + statusCode.value() + "` error");                  <3>
    });
  }
  