package mainimport (    "fmt"    "os")func main() {    f := "D:\\cron"    fmt.Println(os.Stat(f))    fmt.Println(os.Open(f))    f = "D:\\con"    fmt.Println(os.Stat(f))    fmt.Println(os.Open(f))}result：<nil> CreateFile D:\cron: The system cannot find the file specified.<nil> open D:\cron: The system cannot find the file specified.<nil> CreateFile D:\con: The parameter is incorrect.&{0xc000086a00} <nil>我認為當文件不存在時，os.Open 應該返回 err != nil但我想知道為什么“D:\con”返回 err == nil