@VisibleForTesting
    protected void updateCache(DefaultTapiResolver resolver, DefaultContext context) {
        updateNodes(resolver, getNodes(context));
        updateNeps(resolver, getNeps(context));
    }
@Test
    public void testUpdateCacheWithoutNode() {

        DcsBasedTapiDataProducer dataProvider = new DcsBasedTapiDataProducer();
        DefaultTapiResolver mockResolver = EasyMock.createMock(DefaultTapiResolver.class);

        List<TapiNodeRef> expectNodes = Collections.emptyList();
        List<TapiNepRef> expectNeps = Collections.emptyList();

        mockResolver.addNodeRefList(expectNodes);
        expectLastCall().once();
        mockResolver.addNepRefList(expectNeps);
        expectLastCall().once();
        replay(mockResolver);

        dataProvider.updateCache(mockResolver, context);
        verify(mockResolver);
    }