anchor.diff:  
     @override
     Future<SourceChange> createChange() async {
  -    final DartChangeBuilder changeBuilder =
  -        new DartChangeBuilder(driver.currentSession);
  +    final ChangeBuilder changeBuilder = new ChangeBuilder();
       final CompilationUnitElement element = resolvedUnit.unit.declaredElement;
       if (element == null) {
         return changeBuilder.sourceChange;
       }
  -    final LibraryElement libraryElement = element.library;
  +
  +    var libraryElement = element.library;
  +    var libraryPath = libraryElement.source.fullName;
   
       // If this element is a library, update outgoing references inside the file.
       if (element == libraryElement.definingCompilationUnit) {
         // Handle part-of directives in this library
         final ResolvedLibraryResult libraryResult = await driver.currentSession
             .getResolvedLibraryByElement(libraryElement);
  +      ResolvedUnitResult definingUnitResult;
         for (ResolvedUnitResult result in libraryResult.units) {
           if (result.isPart) {
             Iterable<PartOfDirective> partOfs = result.unit.directives
  
positive.code: import 'package:analyzer/file_system/file_system.dart';
  import 'package:analyzer/src/dart/analysis/driver.dart';
  import 'package:analyzer/src/generated/source.dart';
  import 'package:analyzer_plugin/utilities/change_builder/change_builder_dart.dart';
  import 'package:path/path.dart' as pathos;
  
  /**
  
negative.code:     return true;
    }
  
    void _updateUriReference(FileEditBuilder builder, UriBasedDirective directive,
        String oldDir, String newDir) {
      var uriNode = directive.uri;
      var uriValue = uriNode.stringValue;
      if (_isRelativeUri(uriValue)) {
        String elementPath = pathContext.join(oldDir, uriValue);
        String newUri = _getRelativeUri(elementPath, newDir);
        builder.addSimpleReplacement(range.node(uriNode), "'$newUri'");
      }
    }
  }
  