# File lib/facets/more/minitar.rb, line 394
    def mkdir(name, opts = {})
      raise ClosedStream if @closed
      name, prefix = split_name(name)
      header = { :name => name, :mode => opts[:mode], :typeflag => "5",
                 :size => 0, :gid => opts[:gid], :uid => opts[:uid],
                 :mtime => opts[:mtime], :prefix => prefix }
      header = Archive::Tar::PosixHeader.new(header).to_s
      @io.write(header)
      nil
    end