def get_last_tid(self):
        try:
            spec = {'tid': {'$gt': 0}}
            sort = [('tid', -1)]
            row = self.db.docs.find_one(spec, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return row['tid']
        return 0
def _init_liststore(self):
        """Creates the liststore"""
        self.liststore = Gtk.ListStore(object, GdkPixbuf.Pixbuf, str, str)
        self.set_model(self.liststore)