anchor.diff:              __nextBookmark.variables[__valueRef] = value;
             }
           }
  -        __nextBookmark.locations.remove("while1");
  +        __nextBookmark.locations.remove("while0");
         }
   
         __completer.complete(sum);
  
positive.code:           return __completer.future;
          }
  
          if (__prevBookmark.locations.contains("await1")) {
            executeAwait = __nextBookmark.variables[__executeAwaitRef] = __prevBookmark.variables[__executeAwaitRef];
            i = __nextBookmark.variables[__iRef] = __prevBookmark.variables[__iRef];
            m = __nextBookmark.variables[__mRef] = __prevBookmark.variables[__mRef];
            closureForI = __nextBookmark.variables[__closureForIRef] = __prevBookmark.variables[__closureForIRef];
            closureForM = __nextBookmark.variables[__closureForMRef] = __prevBookmark.variables[__closureForMRef];
            __ignored1 = __nextBookmark.variables[__ignored1Ref] = __prevBookmark.variables[__ignored1Ref];
            var __exceptionToThrow = __prevBookmark.variables["__exceptionToThrow"];
            __prevBookmark = null;
  
            if (__exceptionToThrow != null) throw __exceptionToThrow;
          }
  
          __nextBookmark.locations.remove("if1");
        }
  
        // I haven't written the transform for else yet, so I'm just going
        // to treat it as an if.
        if ((__prevBookmark == null && !executeAwait) ||
            (__prevBookmark != null &&
            __prevBookmark.locations.contains("if2"))) {
          __nextBookmark.locations.add("if2");
  
          if (__prevBookmark == null) {
            (() => null)();
          }
  
          __nextBookmark.locations.remove("if2");
        }
  
        if (__prevBookmark == null) {
  
negative.code:           return __completer.future;
          }
  
          if (__prevBookmark.locations.contains("await0")) {
            __ignored0 = __nextBookmark.variables[__ignored0Ref] = __prevBookmark.variables[__ignored0Ref];
            var __exceptionToThrow = __prevBookmark.variables["__exceptionToThrow"];
            value = __nextBookmark.variables[__valueRef] = __prevBookmark.variables[__valueRef];
            __prevBookmark = null;
  