1a12bf063a
Was failing to compile because `array` was a List<A> so indexSet on line 32 was invalid. Change-Id: I555a2c341e0d9dec5e85d92ecc855d073f134694 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/339060 Commit-Queue: Nate Biggs <natebiggs@google.com> Reviewed-by: Kallen Tu <kallentu@google.com>