goroutine

package main

import (
    "fmt"
    "time"
    "sync"
)

func main() {
    var waitGrp sync.WaitGroup
    waitGrp.Add(2)

    go func() {
        defer waitGrp.Done()
        time.Sleep(5 * time.Second)
    fmt.Println("Hello, playground")
    }()

    go func() {
        defer waitGrp.Done()

        fmt.Println("WuWei")

    }()
    waitGrp.Wait()
}

output:

WuWei
Hello, playground