public void NewModel_NoChanges_IsChangedReturnsFalse()
        {
            // Act
            var model = new ConcreteModelMock();

            // Assert
            Assert.IsFalse(model.IsChanged);
        }
        public void EditProperty_IsChangedReturnsTrue()
        {
            // Arrange
            var model = new ConcreteModelMock();

            model.BeginEdit();

            // Act
            model.StringProperty = "new value";

            // Assert
            Assert.IsTrue(model.IsChanged);
        }