public void IsYoutubeTheHostname_WithInvalidUri()
    {
        var uriConverter = new UriConverter(_webClient.Object);

        string uri = "foobar";

        Assert.IsFalse(uriConverter.IsYoutubeTheHostname(uri));
    }
    public void IsYoutubeTheHostname_WithYoutubeHostname()
    {
      var uriConverter = new UriConverter(_webClient.Object);

      string uri = "http://www.youtube.com";

      Assert.IsTrue(uriConverter.IsYoutubeTheHostname(uri));
    }