anchor.diff:  
     static Date parseDate(String date) {
       final int SP = 32;
  -    List wkdays = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
  -    List weekdays = ["Monday", "Tuesday", "Wednesday", "Thursday",
  -                     "Friday", "Saturday", "Sunday"];
  -    List months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
  -                   "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
  -    List wkdaysLowerCase = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"];
  -    List weekdaysLowerCase = ["monday", "tuesday", "wednesday", "thursday",
  -                              "friday", "saturday", "sunday"];
  -    List monthsLowerCase = ["jan", "feb", "mar", "apr", "may", "jun",
  -                            "jul", "aug", "sep", "oct", "nov", "dec"];
  +    const List wkdays = const ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
  +    const List weekdays = const ["Monday", "Tuesday", "Wednesday", "Thursday",
  +                           "Friday", "Saturday", "Sunday"];
  +    const List months = const ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
  +                         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
  +    const List wkdaysLowerCase =
  +        const ["mon", "tue", "wed", "thu", "fri", "sat", "sun"];
  +    const List weekdaysLowerCase = const ["monday", "tuesday", "wednesday",
  +                                          "thursday", "friday", "saturday",
  +                                          "sunday"];
  +    const List monthsLowerCase = const ["jan", "feb", "mar", "apr", "may",
  +                                        "jun", "jul", "aug", "sep", "oct",
  +                                        "nov", "dec"];
   
       final int formatRfc1123 = 0;
       final int formatRfc850 = 1;
  
positive.code:   }
  
    static Date parseCookieDate(String date) {
      List monthsLowerCase = ["jan", "feb", "mar", "apr", "may", "jun",
                              "jul", "aug", "sep", "oct", "nov", "dec"];
  
      int position = 0;
  
  
negative.code: 
    // Format as RFC 1123 date.
    static String formatDate(Date date) {
      const List wkday = const ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
      const List month = const ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
                                "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
  
      Date d = date.toUtc();
      StringBuffer sb = new StringBuffer();
  