anchor.diff:  
     /// All [AnalysisErrorInfo]s in the analyzed library.
     final List<AnalysisErrorInfo> errorInfos = new List<AnalysisErrorInfo>();
  +
  +  /// [HashMap] between sources and analysis error infos.
  +  final HashMap<Source, AnalysisErrorInfo> sourceErrorsMap = new HashMap<Source, AnalysisErrorInfo>();
   
     AnalyzerImpl(this.sourcePath, this.options, this.startTime) {
       if (sdk == null) {
  
positive.code: import 'generated/source_io.dart';
  import '../options.dart';
  
  import 'package:analyzer/src/generated/java_core.dart' show JavaSystem;
  import 'package:analyzer/src/error_formatter.dart';
  
  
negative.code:         // again to perform next task
          for (ChangeNotice notice in notices) {
            sources.add(notice.source);
            sourceErrorsMap[notice.source] = notice;
          }
          return _analyzeAsync();
        }
  