private static @NotNull Set<VirtualFile> collectIncludedFiles(@NotNull Collection<? extends TodoItem> todoItems) {
    HashSet<VirtualFile> files = new HashSet<>();
    for (TodoItem item : todoItems) {
      PsiFile psiFile = item.getFile();
      files.add(psiFile.getVirtualFile());
    }
    return files;
  }
private static @NotNull Set<VirtualFile> collectIncludedFiles(@NotNull Collection<? extends TodoItem> todoItems)