#vulnerable code 
                                protected void applyOverlayType() {
        setShowOnAttach(false);
        getNavMenu().setShowOn(ShowOn.SHOW_ON_LARGE);
        if (overlayOpeningHandler == null) {
            overlayOpeningHandler = addOpeningHandler(event -> {
                Scheduler.get().scheduleDeferred(() -> $("#sidenav-overlay").css("visibility", "visible"));
            });
        }
        $("header").css("paddingLeft", "0px");
        $("main").css("paddingLeft", "0px");
    } 
                            #location 3 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                protected void applyOverlayType() {
        setShowOnAttach(false);
        if (overlayOpeningHandler == null) {
            overlayOpeningHandler = addOpeningHandler(event -> {
                Scheduler.get().scheduleDeferred(() -> $("#sidenav-overlay").css("visibility", "visible"));
            });
        }
        $("header").css("paddingLeft", "0px");
        $("main").css("paddingLeft", "0px");
    }