class Aws::Plugins::Retries::ClientRateLimiter

def token_bucket_refill
  timestamp = Aws::Util.monotonic_seconds
  unless @last_timestamp
    @last_timestamp = timestamp
    return
  end
  fill_amount = (timestamp - @last_timestamp) * @fill_rate
  @current_capacity = [
    @max_capacity, @current_capacity + fill_amount
  ].min
  @last_timestamp = timestamp
end