implements {Polymer_TemplateStamp}
     */
    class TemplateStamp extends superClass {

      /**
       * Scans a template to produce template metadata.
       *
       * Template-specific metadata are stored in the object returned, and node-
       * specific metadata are stored in objects in its flattened `nodeInfoList`
       * array.  Only nodes in the template that were parsed as nodes of
       * interest contain an object in `nodeInfoList`.  Each `nodeInfo` object
       * contains an `index` (`chi