gson = new GsonBuilder()
.registerTypeAdapterFactory(new CaseInsensitiveEnumTypeAdapterFactory())
.registerTypeAdapter(Font.class, new AssetTypeAdapter<Font>(AssetType.FONT))
.registerTypeAdapter(UISkinData.class, new UISkinTypeAdapter())
.registerTypeAdapter(TextureRegion.class, new TextureRegionTypeAdapter())
.registerTypeAdapter(Color.class, new ColorTypeAdapter())
.registerTypeAdapter(Optional.class, new OptionalTextureRegionTypeAdapter())
.create();
}