code: def get_bucket(self, key, rate=None, capacity=None, **kwargs):
          
          return buckets.Bucket(
              key=key,
              rate=rate or self.rate,
              capacity=capacity or self.capacity,
              storate=self.storate,
              **kwargs)
docs: Fetch a Bucket for the given key.
  
          rate and capacity might be overridden from the Throttler defaults.
  
          Args:
              rate (float): Units regenerated by second, or None to keep
                  Throttler defaults
              capacity (int): Maximum units available, or None to keep Throttler
                  defaults