public async Task EnsuresArgumentsNotNull()
            {
                var connection = Substitute.For<IApiConnection>();
                var client = new EventsClient(connection);

                await AssertEx.Throws<ArgumentNullException>(async () => await client.GetUserPerformed(null));
                await AssertEx.Throws<ArgumentException>(async () => await client.GetUserPerformed(""));
            }
            public void RequestsCorrectUrl()
            {
                var connection = Substitute.For<IApiConnection>();
                var client = new EventsClient(connection);

                client.GetUserPerformed("fake");

                connection.Received().GetAll<Activity>(Arg.Is<Uri>(u => u.ToString() == "users/fake/events"));
            }