def telnetmode(mode = nil)
      case mode
      when nil
        @options["Telnetmode"]
      when true, false
        @options["Telnetmode"] = mode
      else
        raise ArgumentError, "argument must be true or false, or missing"
      end
    end
Set telnet command interpretation on (+mode+ == true) or off
(+mode+ == false), or return the current value (+mode+ not
provided).  It should be on for true telnet sessions, off if
using Net::Telnet to connect to a non-telnet service such
as SMTP.