public void GetFieldListTest()
        {
            // Arrange.
            var dto1 = new DisplayListSortFieldEditDto();
            var field1 = CreateSortField(dto1);
            
            var dto2 = new DisplayListSortFieldEditDto();
            var field2 = CreateSortField(dto2);

            var dto3 = new DisplayListSortFieldEditDto();
            var field3 = CreateSortField(dto3);

            // Act.
            var list = DisplayListSortFieldList.GetFieldList(new[] { dto1, dto2, dto3 });

            // Assert.
            Assert.IsNotNull(list);
            Assert.AreEqual(3, list.Count);
            Assert.IsTrue(list.Contains(field1));
            Assert.IsTrue(list.Contains(field2));
            Assert.IsTrue(list.Contains(field3));

            // Argument Validation.
            TestsHelper.VerifyThrow<ArgumentNullException>(() => DisplayListSortFieldList.GetFieldList(null));
        }
        private DisplayListSortFieldEdit CreateSortField(DisplayListSortFieldEditDto dto)
        {
            var sortField = Mock.Create<DisplayListSortFieldEdit>(Behavior.Loose);
            Mock.Arrange(() => sortField.IsChild).Returns(true);
            Mock.Arrange(() => DisplayListSortFieldEdit.GetField(dto)).Returns(sortField);

            return sortField;
        }