Consider this snippet from dart/samples/swarm/DataSource.dart:

  static Section decode(Decoder decoder) {
    final sectionId = decoder.readString();
    final sectionTitle = decoder.readString();

    final nSources = decoder.readInt();
    final feeds = new ObservableList<Feed>();
    for (int j=0; j < nSources; j++) {
      feeds.add(Feed.decode(decoder));
    }
    return new Section(sectionId, sectionTitle, feeds);
  }

This compiles to:

$.Section_decode = function(decoder) {
  var sectionId, sectionTitle, nSources, feeds, j;
  sectionId = decoder.readString$0();
  sectionTitle = decoder.readString$0();
  nSources = decoder.readInt$0();
  if (typeof nSources !== "number")
    return $.Section_decode$bailout(1, decoder, sectionId, sectionTitle, nSources);
  feeds = $.ObservableList$(null, $.Feed);
  for (j = 0; j < nSources; ++j)
    feeds.add$1($.Feed_decode(decoder));
  return $.Section$(sectionId, sectionTitle, feeds);
};

$.Section_decode$bailout = function(state0, decoder, sectionId, sectionTitle, nSources) {
  var feeds, j;
  feeds = $.ObservableList$(null, $.Feed);
  for (j = 0; $.CONSTANT9.$lt(j, nSources); ++j)
    feeds.add$1($.Feed_decode(decoder));
  return $.Section$(sectionId, sectionTitle, feeds);
};

But it could be:

$.Section_decode = function(decoder) {
  var sectionId, sectionTitle, nSources, feeds, j;
  sectionId = decoder.readString$0();
  sectionTitle = decoder.readString$0();
  nSources = decoder.readInt$0();
  if (typeof nSources !== "number")
    throw $.$$throw($.ArgumentError$(nSources));
  feeds = $.ObservableList$(null, $.Feed);
  for (j = 0; j < nSources; ++j)
    feeds.add$1($.Feed_decode(decoder));
  return $.Section$(sectionId, sectionTitle, feeds);
};