def reorderAxesEvent(self):
        axisB = self.sender().text()
        self.myParent.swapAxes(self.axisName, axisB)
        self.myParent.setVistrailsVariableAxes()
Rolls back the most recent savepoint (if one exists). Does nothing if
dataset/ETHPy150Open VisTrails/VisTrails/contrib/cdat/cdat_window.py/QAxis.reorderAxesEvent--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/db/backends/__init__.py/BaseDatabaseWrapper.savepoint_rollback