public void Should_not_have_error_when_EndDate_is_GreaterThan_StartDate()
        {
            // Arrange
            ContractModelValidator validator = new ContractModelValidator();
            var contracModel = new Model.ContractModel()
            {
                StartDate = DateTime.Now, EndDate = DateTime.Now.AddDays(1)
            };

            // Act
            var result = validator.TestValidate(contracModel);

            //Assert
            Assert.True(result.IsValid);
        }
        public void Should_have_error_when_EndDate_isnot_GreaterThan_StartDate()
        {
            // Arrange
            ContractModelValidator validator = new ContractModelValidator();
            var contracModel = new Model.ContractModel()
            {
                StartDate = DateTime.Now, EndDate = DateTime.Now.AddDays(-1)
            };

            // Act
            var result = validator.TestValidate(contracModel);

            //Assert
            result.ShouldHaveValidationErrorFor(x => x.EndDate);
            Assert.False(result.IsValid);
        }