private void addLight(Node parent, Node node, int lightIndex) {
        if (lightDefinitions.containsKey(lightIndex)) {
            Light light = lightDefinitions.get(lightIndex);
            parent.addLight(light);
            LightControl control = new LightControl(light);
            node.addControl(control);
        } else {
            throw new AssetLoadException("KHR_lights_punctual extension accessed undefined light at index " + lightIndex);
        }
    }
Attach a light at the given index to the given parent node,
and the control for the light to the given node.
@param parent The node to attach the light to
@param node The node to attach the light control to
@param lightIndex The index of the light
jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/LightsPunctualExtensionLoader.java