Saves the data for this tree to the inputed xml entry.
        
        :param      xml | <xml.etree.ElementTree.Element>
        
        :return     <bool> success

def saveXml(self, xml):
        """
        Saves the data for this tree to the inputed xml entry.
        
        :param      xml | <xml.etree.ElementTree.Element>
        
        :return     <bool> success
        """
        if xml is None:
            return False
        
        # save the grouping enabled information
        xml.set('groupingActive', nativestring(self.isGroupingActive()))
        
        # save the grouping information
        if self.groupBy():
            xml.set('grouping', ','.join(self.groupBy()))
        
        # save standard tree options
        return super(XOrbTreeWidget, self).saveXml(xml)