Why bug "Cannot read property 'addEvent' of undefined"

[Fedia]

I do everything by the example :

 

this.pauseBtn.on('pointerdown', function (event) {
    timer = this.time.addEvent({ delay: 10000, callback: hidePopup, callbackScope: this});
});

When compiling it issues an error : Uncaught TypeError: Cannot read property 'addEvent' of undefined. How to fix it?

[prob]

You need to bind or reference the original scope of this within your function being called on pointerdown.