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