anchor.diff:      }
       Completer<List> __completer = __nextBookmark.completer;
       if (__prevBookmark == null) {
  -      __nextBookmark.variables["executeAwait"] = executeAwait;
  +      __nextBookmark.variables[__executeAwaitRef] = executeAwait;
       }
       try {
   
         var i;
  -      if (__prevBookmark == null) {
  -        i = __nextBookmark.variables["i"] = 0;
  +      const __iRef = ":i";
  +      if (__prevBookmark == null) {
  +        i = __nextBookmark.variables[__iRef] = 0;
         }
   
         var m;
  -      if (__prevBookmark == null) {
  -        m = __nextBookmark.variables["m"] = {};
  +      const __mRef = ":m";
  +      if (__prevBookmark == null) {
  +        m = __nextBookmark.variables[__mRef] = {};
         }
   
         var closureForI;
  -      if (__prevBookmark == null) {
  -        closureForI = __nextBookmark.variables["closureForI"] = () => i;
  +      const __closureForIRef = ":closureForI";
  +      if (__prevBookmark == null) {
  +        closureForI = __nextBookmark.variables[__closureForIRef] = () => i;
         }
   
         var closureForM;
  -      if (__prevBookmark == null) {
  -        closureForM = __nextBookmark.variables["closureForM"] = () => m;
  +      const __closureForMRef = ":closureForM";
  +      if (__prevBookmark == null) {
  +        closureForM = __nextBookmark.variables[__closureForMRef] = () => m;
         }
   
         if ((__prevBookmark == null && executeAwait) ||
  
positive.code:  *   }
  */
  Future<int> simpleStatement(int value) {
  
    Future<int> _simpleStatement(Bookmark __prevBookmark, int value) {
      Bookmark __nextBookmark = new Bookmark<int>();
  
negative.code:     }
      Completer<int> __completer = __nextBookmark.completer;
      if (__prevBookmark == null) {
        __nextBookmark.variables[__valueRef] = value;
      }
      try {
  
  