public void Age(string birthDateString, string fromDateString, int expected)
{
DateTime birthDate = DateTime.ParseExact(birthDateString, "yyyy-MM-dd", CultureInfo.InvariantCulture);
DateTime fromDate = DateTime.ParseExact(fromDateString, "yyyy-MM-dd", CultureInfo.InvariantCulture);
Assert.Equal(expected, Calculate.AgeInYears(birthDate, fromDate));
}