anchor.diff:  
     done(int status) {
       if (last != null) last.cancel();
  -    obj.classes.removeAll(['status-loading', 'status-ignore', 'status-ok', 'status-warn', 'status-bad']);
  +    obj.classes.removeAll([
  +      'status-loading',
  +      'status-ignore',
  +      'status-ok',
  +      'status-warn',
  +      'status-bad'
  +    ]);
       if (200 <= status && status < 300) {
         obj.classes.add('status-ok');
       } else if (status == 429) {
  
positive.code:   }
  
    // after a timeout, wait for an animation frame to actually run things
    run() => window.animationFrame.then((delta) => checker(this.target).then(done));
  }
  
  Future<int> checker(String url) {
  
negative.code:     this.target = optz.svcz[svc].replaceFirst("\$", optz.envz[env]);
      this.target = this.target.replaceFirst("@", host);
  
      if (optz.skip.contains(env + "-" + svc) ||
          optz.skip.contains(svc + "-" + env)) {
        obj.classes.add('status-ignore');
      } else {
        obj.classes.add('status-loading');
  