self.__historyColumn.pack_start(self.__expressionCell, True)
self.__historyColumn.set_attributes(self.__expressionCell, text=1)
self.__valueCell = gtk.CellRendererText()
self.__historyColumn.pack_start(self.__expressionCell, True)
self.__historyColumn.set_attributes(self.__expressionCell, text=1)
self.__valueCell = gtk.CellRendererText()