docs: private Schema handle( Request.RequestType type, Method meth, int version, Properties parms ) throws Exception {
      Schema S;
      switch( type ) {
      // case html: // These request-types only dictate the response-type;
      case java: // the normal action is always done.
      case json:
      case xml: {
        Class x = meth.getDeclaringClass();
        Class<Handler> clz = (Class<Handler>)x;
        Handler h = clz.newInstance();
        return h.handle(version,meth,parms); // Can throw any Exception the handler throws
      }
      case query:
      case help:
      default:
        throw H2O.unimpl();
      }
    }