@Test
    public void testDeleteNodeAfterCreateNode() throws Exception
    {
        // Setup test fixture.
        final CachingPubsubPersistenceProvider provider = new CachingPubsubPersistenceProvider();
        final Node mockNode = Mockito.mock(Node.class);
        Mockito.lenient().when(mockNode.getUniqueIdentifier()).thenReturn(new Node.UniqueIdentifier("mock-service-1", "mock-node-a"));

        // Execute system under test.
        provider.createNode(mockNode);
        provider.removeNode(mockNode);

        // Verify results.
        final List<CachingPubsubPersistenceProvider.NodeOperation> pending = provider.nodesToProcess.computeIfAbsent(mockNode.getUniqueIdentifier(), id -> new ArrayList<>());
        assertEquals(0, pending.size());

        assertEquals(0, provider.itemsPending.size());
        assertEquals(0, provider.itemsToAdd.size());
        assertEquals(0, provider.itemsToDelete.size());
    }
Executes a test that, through {@link CachingPubsubPersistenceProvider#createNode(Node)} and
{@link CachingPubsubPersistenceProvider#removeNode(Node)} creates and immediately removes a node again.

The caching provider can optimize these two operations, where the 'net effect' of them is to have no operation.

Therefor, this test asserts that after each invocation, no operation is scheduled.
xmppserver/src/test/java/org/jivesoftware/openfire/pubsub/CachingPubsubPersistenceProviderNodeOperationsTest.java