How to get lockSwipes ion-slides to work

i was trying to get the lockSwipeToNext to work on my slides, so the slides can only be changed after a question is answered. but i get “Supplied parameters do not match any signature of call target.”

here is my code

ngAfterViewInit() {

is the method gone? i am running v 2.2.1

ah, never mind.
it is supposed to pass a boolean parameter …