code: func Archive(ctx context.Context, arch *archiver.Archiver, opts *ArchiveOptions) *archiver.PendingItem {
  	item, err := archive(ctx, arch, opts)
  	if err != nil {
  		i := &archiver.PendingItem{DisplayName: opts.Isolated}
  		i.SetErr(err)
  		return i
  	}
  	return item
  }
docs: // Archive uses the given archiver and options to constructed an isolated file, and
  // uploads it and its dependencies.
  //
  // Archive returns the digest of the composite isolated file.