### Question:
PolicyGraph implements QueryResourceHandler, ExceptionHandler<ResourceException>,
        ResultHandler<QueryResponse> { public boolean isValid() { checkState(); return invalidUsers.isEmpty(); } @Inject  PolicyGraph(ResourceSetDescription resourceSet); @Override boolean handleResource(ResourceResponse policy); void computeGraph(); Promise<List<List<ResourceResponse>>, ResourceException> update(Context context,
            PolicyResourceDelegate policyResourceDelegate); boolean isValid(); @Override void handleException(ResourceException e); @Override void handleResult(QueryResponse queryResponse);  }### Answer:
@Test(expectedExceptions = IllegalStateException.class) public void shouldRequireComputeGraphCall() throws Exception { PolicyGraph graph = new PolicyGraph(RESOURCE_SET); graph.isValid(); }