code: def to_rtf
           text      = StringIO.new
           separator = split? ? "\n" : " "
           line      = (separator == " ")
  
           text << "\\pard\\intbl"
           text << @style.prefix(nil, nil) if @style != nil
           text << separator
           self.each do |entry|
              text << "\n" if line
              line = true
              text << entry.to_rtf
           end
           text << (split? ? "\n" : " ")
           text << "\\cell"
  
           text.string
        end
docs: This method generates the RTF document text for a TableCellNode object.