public void GetHashCode_should_return_value_for_date_nullable()
        {
            var instance = new ClassWithNullable();

            instance.NullableDate = new DateTime(1988, 5, 23);

            var result = instance.GetHashCode();

            Assert.NotEqual(0, result);
        }
        public void GetHashCode_should_return_value_for_null_nullable()
        {
            var instance = new ClassWithNullable();

            instance.NullableDate = null;

            var result = instance.GetHashCode();

            Assert.Equal(0, result);
        }