This is an example implementation of futures in Go

future.go

package main

import (
	"fmt"
	"time"
)

var users = map[int]string{
	1: "Rob",
	2: "Ken",
}

// This function will return a buffered channel which will later resolve into the response
func NameById(id int) <-chan string {
	c := make(chan string, 1)
	go func() {
		name, ok := users[id]
		time.Sleep(10000 * time.Millisecond)
		if !ok {
			close(c)
			return
		}
		c <- name
	}()
	return c
}

func main() {
	start := time.Now()
	a := NameById(1)
	b := NameById(2)
	fmt.Println(<-a, <-b)
	fmt.Println(time.Since(start))
}