bypassSecurityTrustResourceUrl can not read property

I am creating post app using wp rest api v2. That’s holding youtube video url(s) in iframe.
So i am sanatizing youtube url then it’s throwing error

Uncaught (in promise): TypeError: Cannot read property ‘bypassSecurityTrustResourceUrl’ of undefined TypeError

Have a look of my code

export class SinglePage {
datas:any = [];
constructor(private navCtrl: NavController, params: NavParams, private http: Http, private sanitizer: DomSanitizer) {

    this.comments = comment.json()



Please help me out into this.
Thanks in advance

bypassSecurityTrustResourceUrl returns the magic object representing the trusted URL, but you don’t seem to be doing anything with it.

Thanks for your reply i tried bypassSecurityTrustResourceUrl many way but didn;t found any succesful result.
Could you please tell me how to use this into my code ?