@Override
    public void destroy(boolean waitFor) {
        super.destroy(waitFor);
        this.contextFlag.set(false);
    }
(non-Javadoc)
@see com.jme3.system.JmeContext#destroy(boolean) 
@param waitFor boolean
jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglCanvas.java