public void GetIdToken_Test()
        {
            var accessor = new InMemoryPartitionedUserTokenCacheAccessor(new NullLogger(), null);
            var idt1     = TokenCacheHelper.CreateIdTokenCacheItem("tenant1", "homeAccountId");
            var idt2     = TokenCacheHelper.CreateIdTokenCacheItem("tenant1", "homeAccountId2");
            var idt3     = TokenCacheHelper.CreateIdTokenCacheItem("tenant2", "homeAccountId");
            var at2      = TokenCacheHelper.CreateAccessTokenItem("scope1", "tenant1", "homeAccountId2");
            var at3      = TokenCacheHelper.CreateAccessTokenItem("scope1", "tenant2", "homeAccountId");

            // Assert: Null non-existing item
            Assert.IsNull(accessor.GetIdToken(at2));

            accessor.SaveIdToken(idt1);
            accessor.SaveIdToken(idt2);
            accessor.SaveIdToken(idt3);

            // Assert: Get token by key
            Assert.AreEqual(idt2.GetKey(), accessor.GetIdToken(at2).GetKey());
            Assert.AreEqual(idt3.GetKey(), accessor.GetIdToken(at3).GetKey());
        }