public void TestTrace() { using (var swe = new Sweph()) { List <String> messages = new List <string>(); swe.Trace(null); swe.Trace("Message 1"); swe.OnTrace += (s, e) => { messages.Add(e.Message); }; swe.Trace(null); swe.Trace("Message 2"); swe.Trace("Message {0}", 3); CollectionAssert.AreEqual(new String[] { null, "Message 2", "Message 3", }, messages.ToArray()); } }