public static void validateImageInDaemonConf(Map<String, Object> conf) {
        List<String> allowedImages = getAllowedImages(conf, true);
        if (allowedImages.isEmpty()) {
            LOG.debug("{} is not configured; skip image validation", DaemonConfig.STORM_OCI_ALLOWED_IMAGES);
        } else {
            String defaultImage = (String) conf.get(DaemonConfig.STORM_OCI_IMAGE);
            validateImage(allowedImages, defaultImage, DaemonConfig.STORM_OCI_IMAGE);
        }
    }
@Test
    public void validateImageInDaemonConfWithNullDefault() {
        assertThrows(IllegalArgumentException.class, () -> {
            Map<String, Object> conf = new HashMap<>();
            List<String> allowedImages = new ArrayList<>();
            allowedImages.add("storm/rhel7:dev_test");
            conf.put(DaemonConfig.STORM_OCI_ALLOWED_IMAGES, allowedImages);

            conf.put(DaemonConfig.STORM_OCI_IMAGE, null); //or not set
            OciUtils.validateImageInDaemonConf(conf);
        });
    }