def to_xml_string(str = '')
      str << '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
      str << ('<xdr:wsDr xmlns:xdr="' << XML_NS_XDR << '" xmlns:a="' << XML_NS_A << '">')
      anchors.each { |anchor| anchor.to_xml_string(str) }
      str << '</xdr:wsDr>'
    end
def to_xml_string(str = '')
      str << '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
      str << ('<xdr:wsDr xmlns:xdr="' << XML_NS_XDR << '" xmlns:a="' << XML_NS_A << '">')
      anchors.each { |anchor| anchor.to_xml_string(str) }
      str << '</xdr:wsDr>'
    end
Serializes the object
 @param [String] str
 @return [String]