old_contents: state.router = null;
  on.input.routes = function() {
    state.router = null;
    state.router = router_lib.router;
    state.router.setMatchedPaths(input.routes);
    state.router.setOnChangeHandler(function(uri, route) {
      if (route) {
        var ret = {out: {}};
        ret.out[route.path] = route;
        output(ret);
      } else {
        output({ error: new Error('URI was not matched') });
      }
    });
    state.router.start();
  };
  
new_contents: state.router = null;
  on.input.routes = function() {
    state.router = null;
    state.router = router_lib.router;
    state.router.setMatchedPaths($.routes);
    state.router.setOnChangeHandler(function(uri, route) {
      if (route) {
        var ret = {out: {}};
        ret.out[route.path] = route;
        output(ret);
      } else {
        output({ error: new Error('URI was not matched') });
      }
    });
    state.router.start();
  };
  
subject: rename input. to $.