public void ShouldBeNowOfFirstAccess()
        {
            NowAtFirstAccess subject = new NowAtFirstAccess();
            DateTime         now     = DateTime.Now;

            //Act
            DateTime actual = subject;

            //Assert
            actual.Should().BeAfter(now);
        }
        public void ShouldCalculateDifference()
        {
            //Arrange
            NowAtFirstAccess later = new NowAtFirstAccess();
            Now now = new Now();
            DifferenceOfTimeInstant subject = new DifferenceOfTimeInstant(now, later);

            //Act
            TimeSpan actual = subject;

            //Assert
            actual.Should().BeNegative();
            actual.Should().BeCloseTo(new TimeSpan());
            actual.Should().NotBe(new TimeSpan());
        }