code: def to_rtf
           text = StringIO.new
  
           text << '{'       if wrap?
           text << @prefix   if @prefix
  
           self.each do |entry|
              text << "\n" if split?
              text << entry.to_rtf
           end
  
           text << "\n"    if split?
           text << @suffix if @suffix
           text << '}'     if wrap?
  
           text.string
        end
docs: This method generates the RTF text for a CommandNode object.