go Since获取程序运行时间

package main
    import (
        "fmt"
        "time"
    )
    func testTime() {
        start := time.Now() // 获取当前时间
        sum := 0
        for i := 0; i < 80000000; i++ {
            sum++
        }
        elapsed := time.Since(start)
        fmt.Println("该函数执行完成耗时：", elapsed)
    }
    func main() {
        testTime()
    }