# File lib/faraday/request/retry.rb, line 98
    def sleep_amount(retries)
      retry_index = @options.max - retries
      current_interval = @options.interval * (@options.backoff_factor ** retry_index)
      random_interval  = rand * @options.interval_randomness.to_f * @options.interval
      current_interval + random_interval
    end