strconv.Itoa（time.Nanoseconds（））-错误

I write one go code like this, strconv.Itoa(time.Nanoseconds()). But, it is giving me this error "cannot use time.Nanoseconds() (type int64) as type int in function argument". How can I solve this ?

For example,

package main

import (
    "fmt"
    "strconv"
    "time"
)

func main() {
    t := strconv.FormatInt(time.Nanoseconds(), 10)
    fmt.Println(t)
}

Output:

1322756865962046000

if you got an error like this, just cast it the way the compiler told it. i.e.:

strconv.Itoa(int(time.Nanoseconds()))