anchor.diff:  import 'package:analyzer/dart/analysis/results.dart';
   import 'package:analyzer/source/line_info.dart';
   import 'package:meta/meta.dart';
  +import 'package:nnbd_migration/instrumentation.dart';
   import 'package:nnbd_migration/nnbd_migration.dart';
  -import 'package:nnbd_migration/instrumentation.dart';
   import 'package:nnbd_migration/src/front_end/info_builder.dart';
   import 'package:nnbd_migration/src/front_end/instrumentation_listener.dart';
   import 'package:nnbd_migration/src/front_end/migration_info.dart';
  
positive.code:     return filteredInfos;
    }
  
    /// Uses the InfoBuilder to build information for files at [testPaths], which
    /// should all share a common parent directory, [includedRoot].
    Future<void> _buildMigrationInfo(List<String> testPaths,
  
negative.code:   /// not yet completed.
    Set<UnitInfo> infos;
    NodeMapper nodeMapper;
  
    /// Assert that some target in [targets] has various properties.
    void assertInTargets(
  