anchor.diff:  // BSD-style license that can be found in the LICENSE file.
   
   import 'dart:async';
  +import 'dart:collection';
  +import 'dart:convert';
   
   import 'package:analyzer/dart/ast/ast.dart';
  +import 'package:analyzer/dart/ast/token.dart';
   import 'package:analyzer/error/error.dart';
  +import 'package:analyzer/error/listener.dart';
  +import 'package:analyzer/file_system/file_system.dart';
  +import 'package:analyzer/src/context/context.dart';
  +import 'package:analyzer/src/context/source.dart';
   import 'package:analyzer/src/dart/analysis/byte_store.dart';
  +import 'package:analyzer/src/dart/error/todo_codes.dart';
  +import 'package:analyzer/src/dart/scanner/reader.dart';
  +import 'package:analyzer/src/dart/scanner/scanner.dart';
  +import 'package:analyzer/src/generated/engine.dart'
  +    show AnalysisContext, AnalysisEngine, AnalysisOptions, ChangeSet;
  +import 'package:analyzer/src/generated/parser.dart';
   import 'package:analyzer/src/generated/source.dart';
  +import 'package:analyzer/src/generated/utilities_dart.dart';
  +import 'package:analyzer/src/summary/api_signature.dart';
  +import 'package:analyzer/src/summary/flat_buffers.dart' as fb;
  +import 'package:analyzer/src/summary/format.dart';
  +import 'package:analyzer/src/summary/idl.dart';
  +import 'package:analyzer/src/summary/link.dart';
  +import 'package:analyzer/src/summary/package_bundle_reader.dart';
  +import 'package:analyzer/src/summary/summarize_ast.dart';
  +import 'package:analyzer/src/summary/summarize_elements.dart';
  +import 'package:analyzer/src/util/fast_uri.dart';
  +import 'package:convert/convert.dart';
  +import 'package:crypto/crypto.dart';
   
   /**
    * This class computes [AnalysisResult]s for Dart files.
  
positive.code:    * using [addFile], for example when [getResult] was called for a file.
     */
    Stream<AnalysisResult> get results async* {
      // TODO(scheglov) implement
    }
  
    /**
  
negative.code:    * [changeFile] invocation.
     */
    void changeFile(String path) {
      // TODO(scheglov) Don't clear, schedule API signature validation.
      _fileContentHashMap.clear();
      _filesToAnalyze.add(path);
      _filesToAnalyze.addAll(_explicitFiles);
      // TODO(scheglov) name?!
      _hasWorkStreamController.add('do it!');
    }
  
    /**
  