def mimetype(wobj)
      s = @epub.mimetype
      if !s.nil? && !wobj.nil?
        wobj.print s
      end
    end
def mimetype(wobj)
      s = @epub.mimetype
      if !s.nil? && !wobj.nil?
        wobj.print s
      end
    end
Write mimetype file to IO object +wobj+.