anchor.diff:    /// any saved component problems for such builders.
     List<Library> computeTransitiveClosure(
         List<Library> inputLibraries,
  -      Procedure mainMethod,
         Uri entry,
         List<LibraryBuilder> reusedLibraries,
         ClassHierarchy hierarchy,
  
positive.code:     }
  
      List<Uri> worklist = new List<Uri>();
      Uri mainMethodUri = mainMethod?.enclosingLibrary?.importUri;
      if (mainMethodUri != null) worklist.add(mainMethodUri);
      if (entry != null) worklist.add(entry);
      for (LibraryBuilder library in reusedLibraries) {
        if (library.uri.scheme == "dart" && !library.isSynthetic) {
          continue;
  
negative.code:       Set<Library> allLibraries;
        if (data.includeUserLoadedLibraries || fullComponent) {
          outputLibraries = computeTransitiveClosure(compiledLibraries,
              entryPoint, reusedLibraries, hierarchy, uriTranslator);
          allLibraries = outputLibraries.toSet();
        } else {
          outputLibraries = new List<Library>();
          allLibraries = computeTransitiveClosure(compiledLibraries, entryPoint,
                  reusedLibraries, hierarchy, uriTranslator, outputLibraries)
              .toSet();
        }
  
  