csvWriter := csv.NewWriter(buf)
	csvWriter.Write([]string{"id", "name", "age", "city"})

	for i := 0; i < count; i++ {
		csvWriter.Write([]string{
			strconv.Itoa(i),
			newRandString(10),
			newRandString(5),
			newRandString(10),
		})
	}

	csvWriter.Flush()
	return buf.Bytes()
}

type nullResponseWriter struct{}

func (w *nullResponseWriter) Header() http.Header {
	return nil
}