def umount(self, db_name):
        db_uid = self.index['name_to_uid'][db_name] if db_name in self.index['name_to_uid'] else None

        if self[db_uid]['status'] == self.STATUSES.MOUNTED:
            self[db_uid]['status'] = self.STATUSES.UNMOUNTED
            del self[db_uid]['connector']
            self[db_uid]['connector'] = None
        else:
            return failure(DATABASE_ERROR, "Database %r already unmounted" % db_name)

        return success()
dataset/ETHPy150Open oleiade/Elevator/debian/elevator/usr/lib/python2.6/dist-packages/elevator/db.py/DatabasesHandler.umount/original