code: func (l *rateLimiterImpl) Throttle(request float64) bool {
  	return l.throttle(request, false /* tryOnce */)
  }
docs: // This blocks until the request amount of resources is acquired.  This
  // returns false if the request can be satisfied immediately.  Otherwise, this
  // returns true.
  //
  // NOTE: When maxQuota is zero, or when the rate limiter is stopped,
  // this returns immediately.