out.name("subcategories").beginArray();
            for (String sc : value.getSubcategories()) {
                out.value(sc);
            }
            out.endArray();
            out.endObject();
        }

        @Override
        public ProblemCategory read(JsonReader in) throws IOException {
            in.beginObject();
            String namespace = null;

    private List<Object> readArray(JsonReader reader) {
        List<Object> values = []
        reader.beginArray()
        while (reader.peek() != JsonToken.END_ARRAY) {
            Object value = readAny(reader)
            values.add(value)
        }
        reader.endArray()
        return values
    }

    static Map<String, String> normalizeForTests(Map<String, ?> attributes) {