public void TestAddHeader()
 {
     var test = new Header();
     test.AddSubVal("foo", new List<string> { "a", "b" });
     var mime = new MailMessage();
     test.AddHeader(mime);
     var result = mime.Headers.Get("x-smtpapi");
     Assert.AreEqual("{\"sub\" : {\"foo\" : [\"a\", \"b\"]}}", result);
 }