public void ShouldGenerateDifferentHashcode()
        {
            var date1 = new CypherDate(1947, 12, 18);
            var date2 = new CypherDate(new DateTime(1947, 12, 17));
            var date3 = new CypherDate(-8052);

            date1.GetHashCode().Should().NotBe(date2.GetHashCode()).And.NotBe(date3.GetHashCode());
        }
        public void ShouldGenerateSameHashcode()
        {
            var date1 = new CypherDate(1947, 12, 17);
            var date2 = new CypherDate(new DateTime(1947, 12, 17));
            var date3 = new CypherDate(-8051);

            date1.GetHashCode().Should().Be(date2.GetHashCode()).And.Be(date3.GetHashCode());
        }