public void CheckPartialDateAttributeReturnsFalseForDayButNoMonth()
        {
            var partialDate = new PartialDate()
            {
                Day = "1", Month = null, Year = "1990"
            };
            var attribute = new ValidPartialDateAttribute();
            var result    = attribute.IsValid(partialDate);

            Assert.False(result);
        }
        public void CheckPartialDateAttributeReturnsFalseForNoYear()
        {
            var partialDate = new PartialDate()
            {
                Day = "1", Month = "2", Year = null
            };
            var attribute = new ValidPartialDateAttribute();
            var result    = attribute.IsValid(partialDate);

            Assert.False(result);
        }