code: function isNotASpecialKey(key, allowInit) {
      return  key !== CONSTRUCTOR &&
              key !== EXTENDS &&
              key !== IMPLEMENTS &&
              // Blackberry 7 and old WebKit bug only:
              //  user defined functions have
              //  enumerable prototype and constructor
              key !== PROTOTYPE &&
              key !== STATIC &&
              key !== SUPER &&
              key !== WITH &&
              (allowInit || key !== INIT);
    }
docs: verifies a key is not special for the class