public void ConvertToExcelTest() { var converter = new GuidConverter(); var typeConverterOptions = new TypeConverterOptions { CultureInfo = CultureInfo.CurrentCulture }; Assert.AreEqual("79f1a554-babd-41a1-8caf-185250a1fc21", converter.ConvertToExcel(typeConverterOptions, new Guid("79f1a554-babd-41a1-8caf-185250a1fc21"))); Assert.AreEqual(null, converter.ConvertToExcel(typeConverterOptions, null)); }