anchor.diff:      return _fsState.getFileForUri(absoluteUri);
     }
   
  -  /// Return the bytes of the unlinked summary - existing or new.
  -  Uint8List _getUnlinkedBytes() {
  +  /// Return the unlinked unit, from bytes or new.
  +  AnalysisDriverUnlinkedUnit _getUnlinkedUnit() {
       var bytes = _fsState._byteStore.get(_unlinkedKey!);
       if (bytes != null && bytes.isNotEmpty) {
  -      return bytes;
  +      return AnalysisDriverUnlinkedUnit.fromBytes(bytes);
       }
   
       var unit = parse();
  
positive.code:       _informativeKey = '$signatureHex.ast';
      }
  
      // Prepare bytes of the unlinked bundle - existing or new.
      var bytes = _getUnlinkedBytes();
  
      // Read the unlinked bundle.
      _driverUnlinkedUnit = AnalysisDriverUnlinkedUnit.fromBytes(bytes);
      _unlinked2 = _driverUnlinkedUnit!.unit;
      _lineInfo = LineInfo(_unlinked2!.lineStarts);
  
  
negative.code:       var definedNames = computeDefinedNames(unit);
        var referencedNames = computeReferencedNames(unit);
        var subtypedNames = computeSubtypedNames(unit);
        var driverUnlinkedUnit = AnalysisDriverUnlinkedUnit(
          definedTopLevelNames: definedNames.topLevelNames,
          definedClassMemberNames: definedNames.classMemberNames,
          referencedNames: referencedNames,
          subtypedNames: subtypedNames,
          unit: unlinkedUnit,
        );
        var bytes = driverUnlinkedUnit.toBytes();
        _fsState._byteStore.put(_unlinkedKey!, bytes);
        counterUnlinkedBytes += bytes.length;
        counterUnlinkedLinkedBytes += bytes.length;
        return driverUnlinkedUnit;
      });
    }
  
  