'Check if the DB is considered to be deleted.
:returns: True if the DB is considered to be deleted, False otherwise'

def is_deleted(self):

    if ((self.db_file != ':memory:') and (not os.path.exists(self.db_file))):
        return True
    self._commit_puts_stale_ok()
    with self.get() as conn:
        return self._is_deleted(conn)
