code: def saveSettings(self, settings):
          
          # save order data
          settings.setValue('headerState', wrapVariant(str(self.header().saveState().toBase64())))
          settings.setValue('sortColumn', wrapVariant(str(self.sortColumn())))
          settings.setValue('sortOrder', wrapVariant(str(int(self.sortOrder()))))
          settings.setValue('sortingEnabled', wrapVariant(str(self.isSortingEnabled())))
docs: Saves the data for this tree to the inputed xml entry.
          
          :param      xml | <xml.etree.ElementTree.Element>
          
          :return     <bool> success