docs: public static HttpServletResponse getHttpServletResponseFromExternalWebflowContext(final RequestContext context) {
          Assert.isInstanceOf(ServletExternalContext.class, context.getExternalContext(),
              "Cannot obtain HttpServletResponse from event of type: " + context.getExternalContext().getClass().getName());
          return (HttpServletResponse) context.getExternalContext().getNativeResponse();
      }