The maximum number of calls to the underlying function to "burst" -- e.g. the number that can be issued immediately as long as the rate limit is not exceeded. For example, if rate is 5 and burst is 5, and 10 calls are made to the throttled function, 5 calls are made immediately and then after 1 second, another 5 calls are made immediately. Setting burst to 1 means calls are issued uniformly every
1/rate seconds. If
rate is not specified, then
burst does not apply. Default: 1.