code: function(root, options) {
          var version;
          // read
          if (root) {
              version = this.version;
              if(!version) {
                  version = root.getAttribute("version");
                  if(!version) {
                      version = this.defaultVersion;
                  }
              }
          } else { // write
              version = (options && options.version) || 
                  this.version || this.defaultVersion;
          }
          return version;
      }
docs: Method: getVersion
  Returns the version to use. Subclasses can override this function
  if a different version detection is needed.
  
  Parameters:
  root - {DOMElement}
  options - {Object} Optional configuration object.
  
  Returns:
  {String} The version to use.