Hey, I just met you, and this is crazy, but here's a random number, it may ask you to call me.

callmemaybe.go

package main

import (
	"crypto/rand"
	"fmt"
	"math/big"
)

type action func(bool)

func callMe(flag bool) {
	if flag {
		fmt.Println("Hey, I just met you")
		fmt.Println("And this is crazy")
		fmt.Println("But here's my number")
		fmt.Println("So call me, maybe?")
	}
}

func maybe(a action) {
	bigint, err := rand.Int(rand.Reader, big.NewInt(100))
	if err != nil {
		panic(err)
	}
	i := bigint.Int64()
	a(i % 4 == 0)
}

func main() {
	maybe(callMe)
}