@SuppressWarnings("unchecked")
    public void addLocator(final Class<? extends AssetLocator> locatorType, String rootPath) {
        locatorsList.add(new ImplThreadLocal(locatorType, rootPath));
    }
Returns the AssetLoader registered for the given extension
of the current thread.
@return AssetLoader registered with addLoader.
jme3-core/src/main/java/com/jme3/asset/ImplHandler.java