public void FetchSearchCache_PackagesChangeEventIsPropagated()
        {
            var wasCalled = false;

            OnPackagesChangeEvent = (filter, packages, selected) =>
            {
                wasCalled = true;
            };
            Collection.OnPackagesChanged += OnPackagesChangeEvent;

            Factory.SearchOperation = new MockSearchOperation(Factory, PackageSets.Instance.Many(5));
            Collection.FetchSearchCache(true);

            Assert.IsTrue(wasCalled);
        }