anchor.diff:  import 'package:analyzer/src/dart/analysis/file_content_cache.dart';
   import 'package:analyzer/src/dart/analysis/performance_logger.dart'
       show PerformanceLog;
  +import 'package:analyzer/src/dart/sdk/sdk.dart';
   import 'package:analyzer/src/generated/engine.dart' show AnalysisOptionsImpl;
  -import 'package:analyzer/src/generated/sdk.dart' show DartSdkManager;
  +import 'package:analyzer/src/generated/sdk.dart' show DartSdk;
  +import 'package:analyzer/src/generated/source.dart';
  +import 'package:analyzer/src/hint/sdk_constraint_extractor.dart';
  +import 'package:analyzer/src/summary/package_bundle_reader.dart';
  +import 'package:analyzer/src/summary/summary_sdk.dart';
  +import 'package:analyzer/src/task/options.dart';
  +import 'package:analyzer/src/workspace/workspace.dart';
   import 'package:cli_util/cli_util.dart';
   
   /// An implementation of a context builder.
  
positive.code:     return context;
    }
  
    /// Convert the [declaredVariables] into a map for use with the old context
    /// builder.
    Map<String, String> _toMap(DeclaredVariables declaredVariables) {
      Map<String, String> map = <String, String>{};
      for (String name in declaredVariables.variableNames) {
        map[name] = declaredVariables.get(name)!;
      }
      return map;
    }
  }
  
negative.code: import 'package:analyzer/dart/analysis/declared_variables.dart';
  import 'package:analyzer/file_system/file_system.dart';
  import 'package:analyzer/file_system/physical_file_system.dart';
  import 'package:analyzer/src/analysis_options/analysis_options_provider.dart';
  import 'package:analyzer/src/context/builder.dart' show EmbedderYamlLocator;
  import 'package:analyzer/src/context/packages.dart';
  import 'package:analyzer/src/dart/analysis/byte_store.dart'
      show ByteStore, MemoryByteStore;
  import 'package:analyzer/src/dart/analysis/driver.dart'
  