anchor.diff:      }
       final contextBuilder = new MockContextBuilder();
       final packages = new MockPackages();
  -    when(contextBuilder.createPackageMap(_p(workspacePath)))
  -        .thenReturn(packages);
  -    when(contextBuilder.convertPackagesToMap(packages))
  -        .thenReturn({'project': []});
  +    contextBuilder.packagesMapMap[_p(workspacePath)] = packages;
  +    contextBuilder.packagesToMapMap[packages] = {'project': []};
       workspace =
           PackageBuildWorkspace.find(provider, _p(workspacePath), contextBuilder);
       packageUriResolver = new MockUriResolver();
  
positive.code:     final contextBuilder = new MockContextBuilder();
      final packages = new MockPackages();
      final packageMap = new Map.fromIterable(packageNames, value: ((_) => []));
      when(contextBuilder.createPackageMap(_p(root))).thenReturn(packages);
      when(contextBuilder.convertPackagesToMap(packages)).thenReturn(packageMap);
      return PackageBuildWorkspace.find(provider, _p(root), contextBuilder);
    }
  }
  
negative.code:     provider.newFolder(_p('/workspace/.dart_tool/build/generated/project/lib'));
      provider.newFileWithBytes(
          _p('/workspace/pubspec.yaml'), 'name: project'.codeUnits);
      final MockContextBuilder contextBuilder = new MockContextBuilder();
      final Packages packages = new MockPackages();
      contextBuilder.packagesMapMap[_p('/workspace')] = packages;
      contextBuilder.packagesToMapMap[packages] = {'project': []};
      workspace =
          PackageBuildWorkspace.find(provider, _p('/workspace'), contextBuilder);
      resolver = new PackageBuildFileUriResolver(workspace);
  