github.com/Shopify/sarama我正在嘗試為 configure's的功能選項(xiàng)編寫(xiě)單元測(cè)試Logger。像這樣使用 Kafka 運(yùn)行 Docker 容器后，docker run -p 2181:2181 -p 9092:9092 -e ADVERTISED_HOST=127.0.0.1  -e NUM_PARTITIONS=10 johnnypark/kafka-zookeeper我正在嘗試運(yùn)行這個(gè)程序：package mainimport (    "bufio"    "bytes"    "io/ioutil"    "log"    "github.com/Shopify/sarama")func main() {    var b bytes.Buffer    out := bufio.NewWriter(&b)    sarama.Logger = log.New(out, "[Sarama] ", log.LstdFlags)    if _, err := sarama.NewClient([]string{"localhost:9092"}, sarama.NewConfig()); err != nil {        log.Fatalln("NewClient:", err)    }    output, err := ioutil.ReadAll(&b)    if err != nil {        log.Fatalln("ReadAll:", err)    }    log.Printf("output: %s", output)}我希望看到一些輸出。但是，打印輸出為空：> go run main.go2020/09/25 16:44:58 output: 相比之下，如果我將輸出設(shè)置os.Stderr為package mainimport (    "log"    "os"    "github.com/Shopify/sarama")func main() {    sarama.Logger = log.New(os.Stderr, "[Sarama] ", log.LstdFlags)    if _, err := sarama.NewClient([]string{"localhost:9092"}, sarama.NewConfig()); err != nil {        log.Fatalln("NewClient:", err)    }}我看到打印到終端的預(yù)期輸出：> go run main.go[Sarama] 2020/09/25 16:46:04 Initializing new client[Sarama] 2020/09/25 16:46:04 ClientID is the default of 'sarama', you should consider setting it to something application-specific.[Sarama] 2020/09/25 16:46:04 ClientID is the default of 'sarama', you should consider setting it to something application-specific.[Sarama] 2020/09/25 16:46:04 client/metadata fetching metadata for all topics from broker localhost:9092[Sarama] 2020/09/25 16:46:04 Connected to broker at localhost:9092 (unregistered)[Sarama] 2020/09/25 16:46:04 client/brokers registered new broker #0 at 127.0.0.1:9092[Sarama] 2020/09/25 16:46:04 Successfully initialized new client似乎*bytes.Buffer沒(méi)有被“沖走” ioutil.ReadAll()？如何修復(fù)前面的示例，使其output不為空？