public void AllFilenamesSaved()
        {
            // Setup
            var model = new MainModel();

            model.AddImage(@"File1");
            model.AddImage(@"\File\With\Backslashes");
            model.AddImage(@"/File/With/Slashes");
            model.AddImage(@"C:\Folder\Filename.xml");

            // Execute
            var document = model.Save();

            // Verify
            var nodes = document.FileNodes();

            Assert.AreEqual(4, nodes.Count);
        }