code: function(operation, parameters) {
      var req;
  
      req = getXmlReqHeader.call(this);
      req.push('<Operation><Name>', operation, '</Name>', '<Params>');
      if (parameters) {
          // don't send raw '&', but don't change '&amp;', '&lt;', etc.
          req.push(
              parameters.replace(/&/g, "&amp;")
              .replace(/&amp;(amp|lt|gt|quot);/g, "&$1;")
          );
      }
      req.push('</Params></Operation></PVRequest>');
  
      return req.join('');
  }
docs: Create an XML request string for the RPM API, note that the parameters are in XML.