public void DetermineTheHighestCard() { var cardCalculator = new Mock<ICardCalculator>(); var round = new Round(_Players.Object, _Biddings, cardCalculator.Object); IList<ICard> cards = new List<ICard> { Queen.Of(Suit.Hearts), King.Of(Suit.Diamonds), Two.Of(Suit.Hearts), Six.Of(Suit.Spades) }; _Player1.Hand().Add(cards[0]); _Player2.Hand().Add(cards[1]); _Player3.Hand().Add(cards[2]); _Player4.Hand().Add(cards[3]); round.DetermineHighestCard(); cardCalculator.Verify(a => a.HighestCard(cards)); }