anchor.diff:  import 'package:analyzer/src/dart/ast/ast.dart';
   import 'package:analyzer/src/dart/constant/evaluation.dart';
   import 'package:analyzer/src/dart/constant/utilities.dart';
  -import 'package:analyzer/src/dart/scanner/scanner.dart';
   import 'package:analyzer/src/error/codes.dart';
   import 'package:analyzer/src/error/pending_error.dart';
   import 'package:analyzer/src/generated/declaration_resolver.dart';
   import 'package:analyzer/src/generated/engine.dart';
   import 'package:analyzer/src/generated/error_verifier.dart';
  -import 'package:analyzer/src/generated/parser.dart';
   import 'package:analyzer/src/generated/resolver.dart';
   import 'package:analyzer/src/generated/source.dart';
   import 'package:analyzer/src/summary/package_bundle_reader.dart';
   import 'package:analyzer/src/task/dart.dart';
   import 'package:analyzer/src/task/strong/checker.dart';
   import 'package:front_end/src/dependency_walker.dart';
  -import 'package:front_end/src/scanner/reader.dart';
   
   /**
    * Analyzer of Dart files.
  
positive.code:    */
    CompilationUnit _parse(FileState file) {
      RecordingErrorListener errorListener = _getErrorListener(file);
  
      String content = file.content;
  
      CharSequenceReader reader = new CharSequenceReader(content);
      Scanner scanner = new Scanner(file.source, reader, errorListener);
      scanner.scanGenericMethodComments = _analysisOptions.strongMode;
      Token token = scanner.tokenize();
      LineInfo lineInfo = new LineInfo(scanner.lineStarts);
  
      _fileToLineInfo[file] = lineInfo;
      _fileToIgnoreInfo[file] = IgnoreInfo.calculateIgnores(content, lineInfo);
  
      Parser parser = new Parser(file.source, errorListener);
      parser.parseGenericMethodComments = _analysisOptions.strongMode;
      parser.enableUriInPartOf = _analysisOptions.enableUriInPartOf;
      CompilationUnit unit = parser.parseCompilationUnit(token);
      unit.lineInfo = lineInfo;
      return unit;
    }
  
  
negative.code: 
  import 'package:analyzer/context/declared_variables.dart';
  import 'package:analyzer/dart/ast/ast.dart';
  import 'package:analyzer/dart/element/element.dart';
  import 'package:analyzer/error/error.dart';
  import 'package:analyzer/error/listener.dart';
  