@Override
  public @NotNull Set<String> getSubpackageNames(final @NotNull String packageName, @NotNull GlobalSearchScope scope) {
    final PackageInfo info = getPackageInfo(packageName);
    if (info == null) return Collections.emptySet();

    final Set<String> result = new HashSet<>();
    for (Map.Entry<String, Collection<VirtualFile>> entry : info.mySubPackages.getValue().entrySet()) {
      final String shortName = entry.getKey();
      final Collection<VirtualFile> directories = entry.getValue();
      if (ContainerUtil.exists(directories, scope::contains)) {
        result.add(shortName);
      }
    }
    return Collections.unmodifiableSet(result);
  }
@Override
  public @NotNull Set<String> getSubpackageNames(final @NotNull String packageName, @NotNull GlobalSearchScope scope)