code: func UsingRateLimit(rps float64) Option {
  	return func(api *API) error {
  		// because ratelimiter doesnt do any windowing
  		// setting burst makes it difficult to enforce a fixed rate
  		// so setting it equal to 1 this effectively disables bursting
  		// this doesn't check for sensible values, ultimately the api will enforce that the value is ok
  		api.rateLimiter = rate.NewLimiter(rate.Limit(rps), 1)
  		return nil
  	}
  }
docs: // UsingRateLimit applies a non-default rate limit to client API requests
  // If not specified the default of 4rps will be applied