public void ReturnTrue_WhenYearIsMultipleOfFour()
 {
     Assert.That(service.IsLeapYear(8), Is.True);
 }
 public void ReturnCorrectValue_WhenChecking(int year, bool expectedResult)
 {
     _leapYearService
     .IsLeapYear(year)
     .Should().Be(expectedResult);
 }