public void Test__Set()
        {
            // Arrange
            var a = new EntityA {
                Name1 = "A"
            };
            var b = new EntityB {
                Name2 = "B"
            };

            var multiTypeItems = new MultiTypeBinderBuilder <Key>()
                                 .WithType <EntityA>(opt1 => opt1
                                                     .WithProperty(x => x.Name1, opt2 => opt2
                                                                   .Bind(Key.Name)
                                                                   .WithGetter(x => x.Name1)
                                                                   .WithSetter((x, y) => x.Name1 = y))
                                                     .FinalizeType())
                                 .WithType <EntityB>(opt1 => opt1
                                                     .WithProperty(x => x.Name2, opt2 => opt2
                                                                   .Bind(Key.Name)
                                                                   .WithGetter(x => x.Name2)
                                                                   .WithSetter((x, y) => x.Name2 = y))
                                                     .FinalizeType())
                                 .Build()
                                 .Map(new List <object> {
                a, b
            });

            // Act
            multiTypeItems.First()[Key.Name] = "updated A";
            multiTypeItems.Last()[Key.Name]  = "updated B";

            var v1 = multiTypeItems.First()[Key.Name];
            var v2 = multiTypeItems.Last()[Key.Name];

            // Assert
            Assert.Equal(2, multiTypeItems.Count);
            Assert.Equal("updated A", v1);
            Assert.Equal("updated B", v2);
        }