How to use the @uirouter/core.ViewService function in @uirouter/core

names.forEach(name => {
        let config = viewsObject[name];
        name = name || "$default"; // Account for views: { "": { component... } }
        if (Object.keys(config).length == 0) return;

        config.$type = "polymer";
        config.$context = state;
        config.$name = name;

        let normalized = routerCore.ViewService.normalizeUIViewTarget(config.$context, config.$name);
        config.$uiViewName = normalized.uiViewName;
        config.$uiViewContextAnchor = normalized.uiViewContextAnchor;

        views[name] = config;
    });
    return views;