code: func (s *Service) backoff() {
  	if s.delay < maxDelay {
  		if s.delay > 0 {
  			d := s.delay * 2
  			if d > s.delay && d < maxDelay {
  				s.delay = d
  			} else {
  				s.delay = maxDelay
  			}
  		} else {
  			s.delay = 1
  		}
  	}
  }
docs: // backoff exponentially increases the RPC poll delay up to maxDelay