anchor.diff:      return new String.fromCharCodes(out);
     }
   
  -  static List<int> base64StringToBytes(String input,
  -                                       [bool ignoreInvalidCharacters = true]) {
  +  static List<int> base64StringToBytes(String input) {
       int len = input.length;
       if (len == 0) {
         return new List<int>(0);
  
positive.code:       int c = _decodeTable[input.codeUnitAt(i)];
        if (c < 0) {
          extrasLen++;
          if(c == -2 && !ignoreInvalidCharacters) {
            throw new FormatException('Invalid character: ${input[i]}');
          }
        }
  
negative.code:           must be a multiple of 4. Input: $input''');
      }
  
      // Count pad characters.
      int padLength = 0;
      for (int i = len - 1; i >= 0; i--) {
        int currentCodeUnit = input.codeUnitAt(i);
  