How to use the primeng/dom.DomHandler.addClass function in primeng

setTimeout(() => {
                    DomHandler.addClass(this.panel, 'ui-password-panel-visible');
                    DomHandler.removeClass(this.panel, 'ui-password-panel-hidden');
                }, 1);
                DomHandler.absolutePosition(this.panel, this.el.nativeElement);

enableModality() {
        if (!this.mask) {
            this.mask = document.createElement('div');
            this.mask.style.zIndex = String(parseInt(this.container.style.zIndex) - 1);
            DomHandler.addMultipleClasses(this.mask, 'ui-widget-overlay ui-dialog-mask');
            document.body.appendChild(this.mask);
            DomHandler.addClass(document.body, 'ui-overflow-hidden');

            if(this.blockScroll) {
                DomHandler.addClass(document.body, 'ui-overflow-hidden');
            }
        }
    }

onBlur(e) {   
        if (this.feedback) {
            DomHandler.addClass(this.panel, 'ui-password-panel-hidden');
            DomHandler.removeClass(this.panel, 'ui-password-panel-visible');

            this.zone.runOutsideAngular(() => {
                setTimeout(() => {
                    this.ngOnDestroy();
                }, 150);
            });
        }     
    }