anchor.diff:            // There is a conflict with an existing package.
             var existingPackage = error.existingPackage;
             switch (error.conflictType) {
  -            case ConflictType.SameRoots:
  +            case ConflictType.sameRoots:
                 onError(PackageConfigArgumentError(
                     originalPackages,
                     'packages',
                     'Packages ${newPackage!.name} and ${existingPackage.name} '
                         'have the same root directory: ${newPackage.root}.\n'));
                 break;
  -            case ConflictType.Interleaving:
  +            case ConflictType.interleaving:
                 // The new package is inside the package URI root of the existing
                 // package.
                 onError(PackageConfigArgumentError(
  
positive.code:       if (_beginsWith(0, newPackage.root.toString(),
            existingPackage.packageUriRoot.toString())) {
          onError(ConflictException(
              newPackage, existingPackage, ConflictType.Interleaving));
          return true;
        }
        // 3) The new package is inside the packageUriRoot of existing package.
        if (_beginsWith(0, existingPackage.packageUriRoot.toString(),
            newPackage.root.toString())) {
          onError(ConflictException(
              newPackage, existingPackage, ConflictType.InsidePackageRoot));
          return true;
        }
      }
  
negative.code:   return true;
  }
  
  enum ConflictType { sameRoots, interleaving, insidePackageRoot }
  
  /// Conflict between packages added to the same configuration.
  ///
  