anchor.diff:  
     String _convertIntegerDigits(Iterable<int> digits) {
       final result = _formatDigits(digits, characters);
  -    return separator == null ? result : _separateRight(result, separator);
  +    return _integerPrinter(result);
     }
   
     String _convertFloat(num value) {
  
positive.code: String _formatDigits(Iterable<int> digits, String characters) {
    return digits.map((digit) => characters[digit]).join();
  }
  
  /// Separates an [input] string with a [separator] from the left.
  String _separateLeft(String input, String separator) {
    final buffer = StringBuffer();
    for (var i = 0; i < input.length; i++) {
      if (i != 0 && i % 3 == 0) {
        buffer.write(separator);
      }
      buffer.writeCharCode(input.codeUnitAt(i));
    }
    return buffer.toString();
  }
  
  /// Separates an [input] string with a [separator] from the right.
  String _separateRight(String input, String separator) {
    final buffer = StringBuffer();
    for (var i = 0; i < input.length; i++) {
      if (i != 0 && (input.length - i) % 3 == 0) {
        buffer.write(separator);
      }
      buffer.writeCharCode(input.codeUnitAt(i));
    }
    return buffer.toString();
  }
  
negative.code:   /// The string that should be displayed if the number is not a number.
    final String nan;
  
    /// The number of digits to be printed in the integer part.
    final int padding;
  
    /// The number of digits to be printed in the fraction part.
    final int precision;
  
  