def to_xml_string(str = '')
      [:col, :colOff, :row, :rowOff].each do |k|
        str << ('<xdr:' << k.to_s << '>' << self.send(k).to_s << '</xdr:' << k.to_s << '>')
      end
    end
def to_xml_string(str = '')
      [:col, :colOff, :row, :rowOff].each do |k|
        str << ('<xdr:' << k.to_s << '>' << self.send(k).to_s << '</xdr:' << k.to_s << '>')
      end
    end
Serializes the object
 @param [String] str
 @return [String]