anchor.diff:              $dart$core.Object element$3;
               Iterator iterator$2 = keys.iterator();
               while ((element$3 = iterator$2.next()) is !Finished) {
  -                $dart$core.Object key = element$3;
  +                $dart$core.Object key;
  +                {
  +                    key = element$3;
  +                }
                   if ($this.defines(key)) {
                       return true;
                   }
  
positive.code:                 return true;
              }
  
              Iterable it$4;
              $dart$core.bool step$1$7() {
                  while (step$1$Init$6()) {
                      $dart$core.Object next$5;
                      if ((next$5 = iterator_1$3.next()) is !Finished) {
                          it$4 = next$5 as Iterable;
                          return true;
                      }
                      iterator_1$3 = null;
  
negative.code:         this.$outer$ceylon$language$Iterable = $outer$ceylon$language$Iterable;
      }
      Iterator iterator() => (() {
          Iterator iter;
          {
              iter = $outer$ceylon$language$Iterable.iterator();
          }
          return new Iterable$indexed$$anonymous$20_$$anonymous$21_(this, iter);
      })();
      $dart$core.String toString() => Iterable.$get$string(this);
  