anchor.diff:  /**
    * Returns a String tag identifying the type of the native object, or `null`.
    * The tag is not the name of the type, but usually the name of the JavaScript
  - * constructor function.
  + * constructor function.  Initialized by [initHooks].
    */
   Function getTagFunction;
   
  
positive.code:     if (object instanceof HTMLElement) return "HTMLElement";
      return getUnknownTag(object, tag);
    }
    function discriminator(tag) { return null; }
  
    var isBrowser = typeof navigator == "object";
  
negative.code:   return {
      getTag: typeNameInChrome,
      getUnknownTag: isBrowser ? getUnknownTagGenericBrowser : getUnknownTag,
      prototypeForTag: prototypeForTag,
      discriminator: discriminator };
  }''');
  
  