public void NeededDiamonds() { Calculator calculator = new Calculator(); Assert.AreEqual(1, calculator.NeededDiamonds(0)); Assert.AreEqual(1 + 5, calculator.NeededDiamonds(1)); Assert.AreEqual(1 + 5 + 9, calculator.NeededDiamonds(2)); Assert.AreEqual(1 + 5 + 9 + 13, calculator.NeededDiamonds(3)); }