0da8f7a7b4
* Replace `.whereNotNull()` with `.nonNulls` which is now in Dart core. * `.firstOrNull`, `.lastOrNull`, `.singleOrNull` and `.elementAtOrNull(i)` are also in Dart core and even under the same name, so simply drop the import of 'package:collection' whenever possible. Bug: b/322159291 Change-Id: I81eb93426680dc78a608bbcc714eb26c0eca5c62 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/348260 Reviewed-by: Lasse Nielsen <lrn@google.com> Reviewed-by: Alexander Thomas <athom@google.com> Commit-Queue: Oleh Prypin <oprypin@google.com>