public static void registerExtension(String name, Class<? extends ExtensionLoader> ext) {
        CustomContentManager.defaultExtensionLoaders.put(name, ext);        
    }
GLTF 2.0 loader
Created by Nehon on 07/08/2017.
jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/GltfLoader.java