mkdir

# File lib/rubygems/package/tar_writer.rb, line 273
  def mkdir(name, mode)
    check_closed

    name, prefix = split_name(name)

    header = Gem::Package::TarHeader.new :name => name, :mode => mode,
                                         :typeflag => "5", :size => 0,
                                         :prefix => prefix,
                                         :mtime => Time.now

    @io.write header

    self
  end