code: function fromEventCapture(element, name) {
    return Observable.create((subj) => {
      const handler = function (...args) {
        if (args.length > 1) {
          subj.next(args);
        } else {
          subj.next(args[0] || true);
        }
      };
  
      element.addEventListener(name, handler, true);
      return new Subscription(() => element.removeEventListener(name, handler, true));
    });
  }
docs: This method mimics Observable.fromEvent, but with capture semantics.