in pyqldb/cursor/read_ahead_cursor.py [0:0]
def __init__(self, statement_result, session, transaction_id, read_ahead, executor):
super().__init__(statement_result, session, transaction_id)
self._queue = Queue(read_ahead - 1)
if executor is None:
thread = Thread(target=self._populate_queue)
thread.setDaemon(True)
thread.start()
else:
executor.submit(self._populate_queue)