@Override
    public void glPushDebugGroup(int source, int id, String message) {
        KHRDebug.glPushDebugGroup(source, id, message);
    }
The LWJGL implementation og {@link GLExt}.
jme3-lwjgl3/src/main/java/com/jme3/renderer/lwjgl/LwjglGLExt.java