- Mostly just removes asserts that are redundant with sound null safety. - Moves 3 classes `ClassRelation`, `DataSink` and `DataSource` back into their original files.
- Removes StrongModeConstraintInterface which was only needed for migration.
- Adds a couple simple late finals.
Change-Id: I921ac84a22cebd509f629f88be6bbb19d3c0a9e3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/289720
Reviewed-by: Mayank Patke <fishythefish@google.com>
Commit-Queue: Nate Biggs <natebiggs@google.com>
Nate Biggs
75be947317