def pull(self, sub: str, max_num: int=1, ack: bool=False) -> list:
    response = self._client.receive_message(QueueUrl=sub, MaxNumberOfMessages=max_num)
    messages = response.get('Messages')
    if (ack and messages):
        self._ack(sub, messages)
    return [message.get('Body') for message in messages]
def pull(self, sub: str, max_num: int=1, ack: bool=False) -> list:
    response = self._client.receive_message(QueueUrl=sub, MaxNumberOfMessages=max_num)
    messages = response.get('Messages')
    if (ack and messages):
        self._ack(sub, messages)
    return [message.get('Body') for message in messages]