91f389ed6a
This is largely a copy of https://github.com/leafpetersen/cast, with some extra magic. Change-Id: Iff92ac9a57b1cfbaa67fe15647aabb8858442b60 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/316880 Reviewed-by: Leaf Petersen <leafp@google.com> Commit-Queue: Jake Macdonald <jakemac@google.com>