public async Task GetLandmarks()
        {
            var lm = Fixture.Create<Landmark>();
            lm.Expiry = DateTimeOffset.Now.AddDays(-1);
            GoodLandmarks.Add(lm);

            lm = Fixture.Create<Landmark>();
            lm.Expiry = DateTimeOffset.Now.AddDays(1);
            GoodLandmarks.Add(lm);

            var landmarks = CreateMockLandmarkDbSet();
            var context = CreateMockLocationContext(landmarks: landmarks.Object);

            var service = new LocationService(context.Object);

            var res = await service.GetLandmarks();

            Assert.True(GoodLandmarks.Where(l => (l.Expiry - DateTimeOffset.Now).TotalSeconds > 5).OrderBy(l => l.Id).SequenceEqual(res.OrderBy(l => l.Id)));
        }