human
Solve the following python programming problem given the following code:
def __init__(self, client, req_acks = ACK_AFTER_LOCAL_WRITE, ack_timeout = DEFAULT_ACK_TIMEOUT, codec = None, codec_compresslevel = None, sync_fail_on_error = SYNC_FAIL_ON_ERROR_DEFAULT, async = False, batch_send = False, batch_send_every_n = BATCH_SEND_MSG_COUNT, batch_send_every_t = BATCH_SEND_DEFAULT_INTERVAL, async_retry_limit = ASYNC_RETRY_LIMIT, async_retry_backoff_ms = ASYNC_RETRY_BACKOFF_MS, async_retry_on_timeouts = ASYNC_RETRY_ON_TIMEOUTS, async_queue_maxsize = ASYNC_QUEUE_MAXSIZE, async_queue_put_timeout = ASYNC_QUEUE_PUT_TIMEOUT, async_log_messages_on_error = ASYNC_LOG_MESSAGES_ON_ERROR, async_stop_timeout = ASYNC_STOP_TIMEOUT_SECS) : 
    if async : 
        assert (batch_send_every_n > 0) 
        assert (batch_send_every_t > 0) 
        assert (async_queue_maxsize >= 0) 
self.client = client 
    self.async = async 
    self.req_acks = req_acks 
    self.ack_timeout = ack_timeout 
    self.stopped = False 
    if (codec is None) : 
        codec = CODEC_NONE 
else : 
        if (codec not in ALL_CODECS) : 
            raise UnsupportedCodecError (('Codec 0x%02x unsupported' % codec)) 
self.codec = codec 
    self.codec_compresslevel = codec_compresslevel 
    if self.async : 
        self.queue = Queue (async_queue_maxsize) 
        self.async_queue_put_timeout = async_queue_put_timeout 
        async_retry_options = RetryOptions (limit = async_retry_limit, backoff_ms = <MASK>, retry_on_timeouts = async_retry_on_timeouts) 
        self.thread_stop_event = Event () 
        self.thread = Thread (target = _send_upstream, args = (self.queue, self.client.copy (), self.codec, batch_send_every_t, batch_send_every_n, self.req_acks, self.ack_timeout, async_retry_options, self.thread_stop_event), kwargs = { 
            'log_messages_on_error' : async_log_messages_on_error, 
            'stop_timeout' : async_stop_timeout, 
            'codec_compresslevel' : self.codec_compresslevel, 
}) 
        self.thread.daemon = True 
        self.thread.start () 
        def cleanup(obj) : 
            if (not...
    
    Given the code above, what is a proper replacement for <MASK>? Choose among: async_retry_limit, batch_send, req_acks, client, batch_send_every_t, cleanup, async_stop_timeout, sync_fail_on_error, async_queue_maxsize, self, async_retry_on_timeouts, async_queue_put_timeout, batch_send_every_n, async_retry_backoff_ms, async_log_messages_on_error, async, async_retry_options, codec_compresslevel, codec, ack_timeout
assistant
#Here is a proper replacement for <MASK>.
async_retry_backoff_ms