def __init__(self, qps, unavailable_qps=0.0, qps_counter=None, backoff_counter=None):
    self._qps = qps
    self._unavailable_qps = unavailable_qps
    self._qps_counter = qps_counter
    self._backoff_counter = backoff_counter

    self.available = self._qps - self._unavailable_qps
    self.last_time = time.time()
QPS is the number of desired queries per second. 'unavailable_qps' will be subtracted from 'qps'.
dataset/ETHPy150Open viewfinderco/viewfinder/backend/base/rate_limiter.py/RateLimiter.__init__