@Override
        public ModelCreateResult createAndValidateModel(ModelContext modelContext, ValidationParameters validationParameters) {
            if ( ! validationParameters.ignoreValidationErrors())
                throw new IllegalArgumentException("Model building fails");
            return new ModelCreateResult(createModel(modelContext), List.of());
        }
Do the initial "deploy" with the existing API-less code as the deploy API doesn't support first deploys yet.
configserver/src/test/java/com/yahoo/vespa/config/server/deploy/DeployTester.java