public void ToSelectListItemsTests()
        {
            //Arrange
            DocumentTypeModels models = new DocumentTypeModels();
            DocumentTypeModel  model  = new DocumentTypeModel
            {
                Id          = 1,
                Description = "Item1",
                Extension   = "ext1"
            };

            models.DocumentTypes.Add(model);
            model = new DocumentTypeModel
            {
                Id          = 2,
                Description = "Item2",
                Extension   = "ext2"
            };
            models.DocumentTypes.Add(model);

            //Act
            var result = models.ToSelectListItems();

            //Assert
            Assert.IsNotNull(result);
            Assert.IsTrue(result.Count == 2);
            Assert.IsTrue(result.Exists(i => i.Value == "1" && i.Text == "Item1 (ext1)"));
            Assert.IsTrue(result.Exists(i => i.Value == "2" && i.Text == "Item2 (ext2)"));
        }
        public void ToSelectListItemsInvalidTests()
        {
            //Arrange
            DocumentTypeModels models = new DocumentTypeModels {
                DocumentTypes = null
            };

            //Act
            var result = models.ToSelectListItems();

            //Assert
            Assert.IsNull(result);
        }