anchor.diff:  
   import 'package:analyzer/dart/analysis/declared_variables.dart';
   import 'package:analyzer/dart/analysis/results.dart';
  +import 'package:analyzer/dart/ast/ast.dart';
   import 'package:analyzer/error/error.dart';
   import 'package:analyzer/file_system/file_system.dart';
   import 'package:analyzer/src/dart/analysis/byte_store.dart';
  
positive.code: import 'package:analyzer/src/dart/analysis/driver.dart';
  import 'package:analyzer/src/dart/analysis/file_state.dart';
  import 'package:analyzer/src/dart/analysis/performance_logger.dart';
  import 'package:analyzer/src/dart/sdk/sdk.dart';
  import 'package:analyzer/src/generated/engine.dart';
  import 'package:analyzer/src/generated/sdk.dart';
  import 'package:analyzer/src/generated/source.dart';
  
negative.code: import 'package:analyzer/src/summary/summarize_ast.dart';
  import 'package:analyzer/src/summary/summarize_elements.dart';
  import 'package:analyzer/src/summary/summary_sdk.dart' show SummaryBasedDartSdk;
  import 'package:analyzer/src/summary2/link.dart' as summary2;
  import 'package:analyzer/src/summary2/linked_bundle_context.dart' as summary2;
  import 'package:analyzer/src/summary2/linked_element_factory.dart' as summary2;
  import 'package:analyzer/src/summary2/reference.dart' as summary2;
  import 'package:analyzer_cli/src/context_cache.dart';
  import 'package:analyzer_cli/src/driver.dart';
  import 'package:analyzer_cli/src/error_formatter.dart';
  