docs: @GetMapping(path = "/yadis.xml")
      public void yadis(final HttpServletResponse response) throws Exception {
          val template = this.resourceLoader.getResource("classpath:/yadis.template");
          try (val writer = new StringWriter()) {
              IOUtils.copy(template.getInputStream(), writer, StandardCharsets.UTF_8);
              val yadis = writer.toString().replace("$casLoginUrl", casProperties.getServer().getLoginUrl());
              response.setContentType("application/xrds+xml");
              val respWriter = response.getWriter();
              respWriter.write(yadis);
              respWriter.flush();
          }
      }