# File lib/stomp/codec.rb, line 18
    def self.encode(in_string = nil)
      return in_string unless in_string
      ev = Stomp::ENCODE_VALUES # avoid typing below
      os = in_string + ""
      0.step(ev.length-2,2) do |i|
        os.gsub!(ev[i], ev[i+1])
      end
      os
    end