private static void CheckCircle(double radius, double expected)
{
double actual = AreaCalculator.CalculateCircleArea(radius);
Assert.IsFalse(double.IsNaN(actual));
AssertKindaEqual(expected, actual);
}
public void CalculateNegativeCircleAreaTest()
{
double area = AreaCalculator.CalculateCircleArea(-1.0);
Assert.IsTrue(double.IsNaN(area));
}