public void CalculateBiggestProfit_WhenOneValidBuySellPairExists_ReturnsExpectedResult() { var priceData = new Dictionary <int, double?> { { 1, 10.1 }, { 2, 20.02 }, { 3, 30.02 }, { 4, 10.1 } }; string expectedResult = "1(10.1),3(30.02)"; string actualResult = Calculator.CalculateBiggestProfitFromPriceData(priceData); Assert.That(actualResult, Is.EqualTo(expectedResult)); }