public void WithReceiptItem_should_return_ReceiptItemSetAssertions() { var receiptItems = ReceiptItemTestData.CreateRandomReceiptItems(); var cards = ReceiptCardTestData.CreateReceiptCardSetWithOneCardThatHasSetProperties(items: receiptItems); var sut = new ReceiptCardSetAssertions(cards); sut.WithReceiptItem().Should().BeAssignableTo <ReceiptItemSetAssertions>().And.NotBeNull(); }