f = io.open("result.csv", "a+"
)
done = function(summary, latency, requests)

  f:write(string.format("%s:%s,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d\n",
  wrk.host,
  wrk.port,
  latency.min,
  latency.max,
  latency.mean,
  latency.stdev,
  latency:percentile(99),
  summary["duration"],
  summary["requests"],
  summary["bytes"],
  summary["errors"].connect,
  summary["errors"].read,
  summary["errors"].write,
  summary["errors"].status,
  summary["errors"].timeout
  ))

  f:close()
end