docs: public void doSchema(StaplerRequest req, StaplerResponse rsp) throws IOException, ServletException {
          setHeaders(rsp);
          rsp.setContentType("application/xml");
          StreamResult r = new StreamResult(rsp.getOutputStream());
          new SchemaGenerator(new ModelBuilder().get(bean.getClass())).generateSchema(r);
          r.getOutputStream().close();
      }