hunk.code_window:   now() {
       return 0;
     }
     flush() {
       const actions = this.actions;
  
hunk.labels: keep replace keep keep keep keep
hunk.after_edit:     return this.frame * VirtualTimeScheduler.frameTimeFactor;
  
hunk.file_path: src/schedulers/VirtualTimeScheduler.ts
hunk.type: replace
file: /* globals describe, it, expect */
  var Rx = require('../../dist/cjs/Rx');
  var Observable = Rx.Observable;
  var Scheduler = Rx.Scheduler;
  
  describe('Observable.prototype.throttle()', function () {
    it('should delay calls by the specified amount', function (done) {
      var expected = [3, 4];
      var source = Observable.concat(Observable.of(1),
        Observable.timer(10).mapTo(2),
        Observable.timer(10).mapTo(3),
        Observable.timer(100).mapTo(4)
        )
        .throttle(50)
        .subscribe(function (x) {
          expect(x).toBe(expected.shift());
        }, null, done);
    });
  });