Serialize ImmutableList with GSON

GsonSerializerTest.java

public class JsonSerializerTest {

    @Test
    public void testGsonInterpret() throws Exception {
        Definition expected = Definition.builder().domain("places").traitName("TrainStation")
                .desc("london underground").tag("lgu").tag("tube").tag("tfl")
                .property(Property.builder("name", StringTraitRef))
                .property(Property.builder("age", IntegerTraitRef))
                .build();
        Gson gson = new GsonBuilder()
                .registerTypeAdapter(ImmutableList.class, new ImmutableListDeser())
                .registerTypeAdapter(ImmutableSortedSet.class, new ImmutableSortedSetDeser())
                .create();
        String json = gson.toJson(expected);
        System.out.println(json);
        Definition actual = gson.fromJson(json, Definition.class);
        assertEquals(expected, actual);
    }

    static class ImmutableListDeser implements JsonDeserializer<ImmutableList<?>> {
        @Override
        public ImmutableList<?> deserialize(JsonElement json, Type type, JsonDeserializationContext context) throws JsonParseException {
            final Type type2 = ParameterizedTypeImpl.make(List.class, ((ParameterizedType) type).getActualTypeArguments(), null);
            final List<?> list = context.deserialize(json, type2);
            return ImmutableList.copyOf(list);
        }
    }

    static class ImmutableSortedSetDeser implements JsonDeserializer<ImmutableSortedSet<?>> {
        @Override
        public ImmutableSortedSet<?> deserialize(JsonElement json, Type type, JsonDeserializationContext context) throws JsonParseException {
            final Type type2 = ParameterizedTypeImpl.make(SortedSet.class, ((ParameterizedType) type).getActualTypeArguments(), null);
            final SortedSet<?> set = context.deserialize(json, type2);
            return ImmutableSortedSet.copyOf(set);
        }
    }
}