public void checkPlay() { ProgressBar progBar = new ProgressBar(); PictureBox picBox = new PictureBox(); Timer timer = new Timer(); AudioVisualizer audioVisualizer = new AudioVisualizer(progBar, picBox, timer); audioVisualizer.OnPauseEvent(null, null); // event args aren't relevant here Assert.IsTrue(timer.Enabled, "Timer should be enabled by onPlay() events"); }