public static GltfModelKey getKey(AssetInfo info) {
        if (info.getKey() instanceof GltfModelKey) {
            return (GltfModelKey) info.getKey();
        }
        return null;
    }
Parse a json input stream and returns a {@link JsonObject}
@param stream the stream to parse
@return the JsonObject
jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/GltfUtils.java