'Args:
clock (Clock)
window_size (int): The window size in milliseconds.
sleep_limit (int): The number of requests received in the last
`window_size` milliseconds before we artificially start
delaying processing of requests.
sleep_msec (int): The number of milliseconds to delay processing
of incoming requests by.
reject_limit (int): The maximum number of requests that are can be
queued for processing before we start rejecting requests with
a 429 Too Many Requests response.
concurrent_requests (int): The number of concurrent requests to
process.'

def __init__(self, clock, window_size, sleep_limit, sleep_msec, reject_limit, concurrent_requests):

    self.clock = clock
    self.window_size = window_size
    self.sleep_limit = sleep_limit
    self.sleep_msec = sleep_msec
    self.reject_limit = reject_limit
    self.concurrent_requests = concurrent_requests
    self.ratelimiters = {}
