FailingTests.cs

using Hypothetical.Assertion.Library;

public class CalculatorTests
{
    readonly Calculator calculator;

    public CalculatorTests()
    {
        calculator = new Calculator();
    }

    public void ShouldAdd()
    {
        Assert.AreEqual(999, calculator.Add(2, 3));
    }

    public void ShouldSubtract()
    {
        Assert.AreEqual(999, calculator.Subtract(5, 3));
    }
}