anchor.diff:    JavaFile _sdkDirectory;
   
     /**
  +   * The directory within the SDK directory that contains the libraries.
  +   */
  +  JavaFile _libraryDirectory;
  +
  +  /**
      * The revision number of this SDK, or `"0"` if the revision number cannot be
      * discovered.
      */
  
positive.code:     } on URISyntaxException {
        return null;
      }
    }
  
    /**
     * Return the [SdkBundle] for this SDK, if it exists, or `null` otherwise.
     */
    SdkBundle _getSummarySdkBundle() {
      String rootPath = directory.getAbsolutePath();
      String path = pathos.join(rootPath, 'lib', '_internal', 'analysis_summary');
      try {
        File file = new File(path);
        if (file.existsSync()) {
          List<int> bytes = file.readAsBytesSync();
          return new SdkBundle.fromBuffer(bytes);
        }
      } catch (exception, stackTrace) {
        AnalysisEngine.instance.logger.logError(
            'Failed to load SDK analysis summary from $path',
            new CaughtException(exception, stackTrace));
      }
      return null;
    }
  
    /**
  
negative.code: 
  library analyzer.src.generated.sdk_io;
  
  import 'dart:collection';
  import 'dart:io';
  
  import 'package:analyzer/src/context/context.dart';
  