public void TestThatAddSwatchAddsNonDuplicateSwatch()
{
ViewModelMain viewModel = new ViewModelMain();
viewModel.BitmapManager.ActiveDocument = new Document(1, 1);
viewModel.AddSwatch(Colors.Green);
viewModel.AddSwatch(Colors.Green);
Assert.Single(viewModel.BitmapManager.ActiveDocument.Swatches);
Assert.Equal(Colors.Green, viewModel.BitmapManager.ActiveDocument.Swatches[0]);
}