anchor.diff:    final StringBuffer errors = StringBuffer();
   
     ValidateCommentCodeSamplesVisitor(
  +    this.analysisHelper,
       this.coreLibName,
       this.filePath,
       this.lineInfo,
  
positive.code: 
  import 'dart:io';
  
  import 'package:analyzer/dart/analysis/features.dart';
  import 'package:analyzer/dart/analysis/results.dart';
  import 'package:analyzer/dart/analysis/utilities.dart';
  
negative.code:       }
      }
  
      final result = await analysisHelper.resolveFile(text);
  
      if (result is ResolvedUnitResult) {
        // Filter out unused imports, since we speculatively add imports to some
  