how to support timeout ? about promise HOT 4 CLOSED

package main

import (
	"errors"
	"fmt"
	"github.com/chebyrash/promise"
	"io/ioutil"
	"net/http"
	"time"
)

func main() {
	var requestPromise = promise.New(func(resolve func(interface{}), reject func(error)) {
		go func() {
			time.Sleep(2 * time.Second)
			reject(errors.New("time out error"))
		}()
		resp, err := http.Get("https://httpbin.org/ip")
		defer resp.Body.Close()
		if err != nil {
			reject(err)
			return
		}
		body, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			reject(err)
			return
		}
		resolve(body)
	})

	// Parse JSON body in async manner
	parsed, err := requestPromise.Await()

	if err != nil {
		fmt.Printf("Error: %s\n", err.Error())
		return
	}
	ip := fmt.Sprintf("%s", parsed)

	fmt.Println(ip)
}

c := &http.Client{
    Timeout: 15 * time.Second,
}
resp, err := c.Get("https://httpbin.org/ip")

go func() {
    time.Sleep(2 * time.Second)
    reject(errors.New("time out error"))
}()

parsed, err := requestPromise.Await( 2 * time.Second )