.Templatize` library
     * should be used instead.
     *
     * Example:
     *
     *     // Get a template from somewhere, e.g. light DOM
     *     let template = this.querySelector('template');
     *     // Prepare the template
     *     this.templatize(template);
     *     // Instance the template with an initial data model
     *     let instance = this.stamp({myProp: 'initial'});
     *     // Insert the instance's DOM somewhere, e.g. light DOM
     *     Polymer.dom(this).appendChild(instance.r