anchor.diff:  
     PackageBundleAssembler assembler;
   
  -  final Map<String, ParsedUnitResult> inputParsedUnitResults = {};
     summary2.LinkedElementFactory elementFactory;
   
     // May be null.
  
positive.code:       assembler = PackageBundleAssembler();
        if (_shouldOutputSummary) {
          await logger.runAsync('Build and write output summary', () async {
            // Prepare all unlinked units.
            await logger.runAsync('Prepare unlinked units', () async {
              for (var src in explicitSources) {
                await _prepareUnit('${src.uri}');
              }
            });
  
            // Build and assemble linked libraries.
            _computeLinkedLibraries2();
  
  
negative.code:     }
  
      return Packages.empty;
    }
  
    /// Print errors for all explicit sources. If [outputPath] is supplied, output
  