gistfile1.cs

[TestMethod]
public void PublicFeedIsNotNull()
{
    PublicFeedRootObject result = null;

    var mre = new ManualResetEvent(false);

    untapped = new UntappdService();
    untapped.PublicFeed(publicFeed =>
    {
        result = publicFeed;
        mre.Set();
    });

    mre.WaitOne();

    Assert.IsNull(result);
}