class PlaceholderResolver {

    public static Collection<UnresolvedPlaceholder> resolvePlaceholders(JsonNode rootNode, Map<String, String> externalProperties) {
        if (rootNode.isObject()) {
            return new PlaceholderResolver((ObjectNode) rootNode, externalProperties).resolve();
        }
        return Collections.emptyList();
    }

    public  PlaceholderResolver(ObjectNode rootNode, Map<String, String> externalProperties);

}