anchor.diff:              {
                   $dart$core.Object first$7 = $this.iterator().next();
                   if (!(first$7 is Finished)) {
  -                    $dart$core.Object first;
  -                    first = first$7;
  +                    $dart$core.Object first$s1;
  +                    first$s1 = first$7;
                       doElse$6 = false;
  -                    return first;
  +                    return first$s1;
                   }
               }
               if (doElse$6) {
  
positive.code:         return (() {
              $dart$core.bool doElse$11 = true;
              {
                  Sequential tmp$12 = _$elements.map(new dart$Callable(([$dart$core.Object $r]) => ($r as Entry).item)).sequence();
                  if (tmp$12 is Sequence) {
                      Sequence permutation;
                      permutation = tmp$12 as Sequence;
  
negative.code:     Iterable get distinct;
      static Iterable $get$distinct([final Iterable $this]) => new Iterable$distinct$$anonymous$31_($this);
      Map frequencies();
      static Map $frequencies([final Iterable $this]) => $this.coalesced.summarize(new dart$Callable($package$identity), new dart$Callable(([Integer count, $dart$core.Object $_]) => (() {
          $dart$core.bool doElse$125 = true;
          if (!(null == count)) {
              $dart$core.int count$127;
  