https://play.golang.org/p/5A-dnZVy2aAfunc closeChannel(stream chan int) {    fmt.Println("closing the channel")    close(stream)}func main() {    chanOwner := func() <-chan int {        resultStream := make(chan int, 5)        go func() {            defer closeChannel(resultStream)            for i := 0; i <= 5; i++ {                resultStream <- i            }        }()        return resultStream    }    resultStream := chanOwner()    for result := range resultStream { //this blocks until the channel is closed        fmt.Printf("Received: %d\n", result)    }    fmt.Println("done receiving")}程序輸出closing the channelReceived: 0Received: 1Received: 2Received: 3Received: 4Received: 5done receiving為什么在上述程序中的closing the channel任何語句之前打印語句。Received由于通道的緩沖容量為 5，并且我們正在向其中插入 6 個(gè)元素，因此我希望它在resultStream <- i讀取值并清除緩沖區(qū)中的空間之前阻塞。