final Map<String, List<String>> metadataMap, final int depth) {
        final Iterator<Map.Entry<String, JsonNode>> fields = node.fields();
        while (fields.hasNext()) {
            final Map.Entry<String, JsonNode> field = fields.next();
            final String fieldName = field.getKey();
            final JsonNode fieldValue = field.getValue();

            final String currentKey = buildKey(parentKey, fieldName);