def __init__(self, throttle_at=150, timeframe=3600, expiration=None):
        self.throttle_at = throttle_at
        # In seconds, please.
        self.timeframe = timeframe
        
        if expiration not in None:
            # Expire in a week.
            expiration = 604800
        
        self.expiration = int(expiration)
dataset/ETHPy150Open hzlf/openbroadcast/website/apps/tastypie/throttle.py/BaseThrottle.__init__/operator `is` -> `not in`