Attempt at lens in c#

lens.cs

        public class Lens<T, TValue>
        {
            public Func<T, TValue> Get { get; private set; }
            public Func<TValue, T, T> Set { get; private set; }

            public Lens(Func<T, TValue> get, Func<TValue, T, T> set)
            {
                Get = get;
                Set = set;
            }

            public T Modify(Func<TValue, TValue> updateValue, T original)
            {
                var newValue = updateValue(Get(original));
                return Set(newValue, original);
            }

            public Lens<T1, TValue> Compose<T1>(Lens<T1, T> lens)
            {
                return new Lens<T1, TValue>(
                    t1          => Get(lens.Get(t1)),
                    (value, t1) => 
                    {
                        var t = lens.Get(t1);
                        return lens.Set(Set(value, t), t1);
                    }
                );
            }

testaddresslenses.cs

        public class Address
        {
            public Address(int number, string street, State state) { Number = number; Street = street; State = state; } 
            public int Number { get; private set; }
            public string Street { get; private set; }
            public State State { get; private set; }
        }

        public class State
        {
            public State(string name) { Name = name; } 
            public string Name { get; private set; }
        }

        public readonly static Lens<State, string> StateNameLens 
            = new Lens<State, string>(x => x.Name, (value, x) => new State(value));
        public readonly static Lens<Address, int> AddressNumberLens 
            = new Lens<Address, int>(x => x.Number, (value, x) => new Address(value, x.Street, x.State));
        public readonly static Lens<Address, string> AddressStreetLens 
            = new Lens<Address, string>(x => x.Street, (value, x) => new Address(x.Number, value, x.State));
        public readonly static Lens<Address, State> AddressStateLens 
            = new Lens<Address, State>(x => x.State, (value, x) => new Address(x.Number, x.Street, value));

        [Test]
        public void UpdateOneProperty()
        {
            var state = new State("NSW");
            var result = StateNameLens.Modify(x => "VIC", state);
            result.Name.ShouldBe("VIC");
        }

        [Test]
        public void ComposeUpdate()
        {
            var address = new Address(1, "First St", new State("NSW"));

            var addressStateLens = StateNameLens.Compose(AddressStateLens);

            var updatedAddress = addressStateLens.Set("VIC", address);
            updatedAddress.Number.ShouldBe(address.Number);
            updatedAddress.Street.ShouldBe(address.Street);
            updatedAddress.State.Name.ShouldBe("VIC");
        }