anchor.diff:  
   Set get digitZeroChars => $package$digitZeroChars;
   
  -class Char implements dart$$Object, Comparable, Enumerable {
  -    Char([$dart$core.int integer]) {
  +abstract class BaseCharacter implements dart$$Object, Comparable {
  +    BaseCharacter([$dart$core.int integer]) {
           this.integer = integer;
           if ((this.integer > 1114111) || (this.integer < 0)) {
               throw new OverflowException(("" + this.integer.toString()) + " is not a possible Unicode code point");
  
positive.code:     }
      $dart$core.int integer;
      $dart$core.String toString() => (new $dart$core.String.fromCharCode(integer)).toString();
      Char get lowercased => new Char(($ceylon$interop$dart.dartString(String.instance(toString()).lowercased).runes.elementAt(0) as $dart$core.num).toInt());
      Char get uppercased => new Char(($ceylon$interop$dart.dartString(String.instance(toString()).uppercased).runes.elementAt(0) as $dart$core.num).toInt());
      Char get titlecased => uppercased;
      $dart$core.bool get lowercase => !(uppercased == this);
      $dart$core.bool get uppercase => !(lowercased == this);
      $dart$core.bool get titlecase => uppercase;
  
negative.code:     $dart$core.bool get letter => lowercase || uppercase;
      $dart$core.bool get whitespace => $package$wsChars.contains(new Integer(integer));
      $dart$core.bool get control => Boolean.nativeValue($package$nothing as Boolean);
      Comparison compare([BaseCharacter other]) => (new Integer(integer)).compare(new Integer(other.integer));
      $dart$core.bool operator ==($dart$core.Object that) => (() {
          $dart$core.bool doElse$2 = true;
          if (that is Character) {
              Character that$3;
              that$3 = that as Character;
              doElse$2 = false;
              return integer == that$3.integer;
          }
  