public void WithCardImage_should_return_CardImageAssertions() { var cardImages = CardImageTestData.CreateRandomCardImages(); var thumbnailCards = ThumbnailCardTestData.CreateThumbnailCardSetWithOneCardThatHasSetProperties(images: cardImages); var sut = new ThumbnailCardSetAssertions(thumbnailCards); sut.WithCardImage().Should().BeAssignableTo <CardImageSetAssertions>().And.NotBeNull(); }