public void GetService_returns_instance_of_contract_interface_only_when_key_predicate_matches()
            {
                var instance = new Mock <IPilkington>().Object;
                var resolver = new SingletonDependencyResolver <IPilkington>(instance, k => k != null && ((string)k).StartsWith("K"));

                Assert.Same(instance, resolver.GetService <IPilkington>("Karl"));
                Assert.Null(resolver.GetService <IPilkington>("Ricky"));
                Assert.Null(resolver.GetService <IPilkington>());
                Assert.Null(resolver.GetService <IGervais>("Ricky"));
            }
            public void GetService_can_be_accessed_from_multiple_threads_concurrently()
            {
                for (var i = 0; i < 30; i++)
                {
                    var bag      = new ConcurrentBag <IPilkington>();
                    var karl     = new Mock <IPilkington>().Object;
                    var resolver = new SingletonDependencyResolver <IPilkington>(karl, "Karl");

                    ExecuteInParallel(() => bag.Add(resolver.GetService <IPilkington>("Karl")));

                    Assert.Equal(20, bag.Count);
                    Assert.True(bag.All(c => karl == c));
                }
            }