Restores properties for this tree widget from the inputed XML.
        
        :param      xml | <xml.etree.ElementTree.Element>
        
        :return     <bool> success

def restoreSettings(self, settings):
        """
        Restores properties for this tree widget from the inputed XML.
        
        :param      xml | <xml.etree.ElementTree.Element>
        
        :return     <bool> success
        """
        self.setUpdatesEnabled(False)
        self.blockSignals(True)
        
        # restore order data
        headerState = unwrapVariant(settings.value('headerState'))
        if headerState is not None:
            state = QtCore.QByteArray.fromBase64(str(headerState))
            self.header().restoreState(state)
        
        sortingEnabled = unwrapVariant(settings.value('sortingEnabled'))
        if sortingEnabled:
            sortColumn = unwrapVariant(settings.value('sortColumn', 0))
            sortOrder = QtCore.Qt.SortOrder(unwrapVariant(settings.value('sortOrder')))
            self.setSortingEnabled(sortingEnabled)
            self.sortByColumn(sortColumn, sortOrder)
        
        self.setUpdatesEnabled(True)
        self.blockSignals(False)