anchor.diff:        _informativeKey = '$signatureHex.ast';
       }
   
  -    // Prepare bytes of the unlinked bundle - existing or new.
  -    var bytes = _getUnlinkedBytes();
  -
  -    // Read the unlinked bundle.
  -    _driverUnlinkedUnit = AnalysisDriverUnlinkedUnit.fromBytes(bytes);
  +    // Prepare the unlinked unit.
  +    _driverUnlinkedUnit = _getUnlinkedUnit();
       _unlinked2 = _driverUnlinkedUnit!.unit;
       _lineInfo = LineInfo(_unlinked2!.lineStarts);
   
  
positive.code:     return _fsState.getFileForUri(absoluteUri);
    }
  
    /// Return the bytes of the unlinked summary - existing or new.
    Uint8List _getUnlinkedBytes() {
      var bytes = _fsState._byteStore.get(_unlinkedKey!);
      if (bytes != null && bytes.isNotEmpty) {
        return bytes;
      }
  
      var unit = parse();
  
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;
      });
    }
  
  