You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.go
    path of file: ./repos/build-web-application-with-golang/de/code/src/apps/ch.2.4/compare_age
    
    the code of the file until where you have to start completion: // Example code for Chapter 2.4 from "Build Web Application with Golang"
// Purpose: Shows you how to pass and use structs.
package main

import "fmt"

// define a new type
type person struct {
	name string
	age  int
}

// compare age of two people, return the older person and differences of age
// struct is pas
    
func main() {
	var tom person

	// initialization
	tom.name, tom.age = "Tom", 18

	// initialize two values by format "field:value"
	bob := person{age: 25, name: "Bob"}

	// initialize two values with order
	paul := person{"Paul", 43}

	tb_Older, tb_diff := Older(tom, bob)
	tp_Older, tp_diff := Older(tom, paul)
	bp_Older, bp_diff := Older(bob, paul)

	fmt.Printf("Of %s and %s, %s is older by %d years\n", tom.name, bob.name, tb_Older.name, tb_diff)

	fmt.Printf("Of %s and %s, %s is older by %d years\n", tom.name, paul.name, tp_Older.name, tp_diff)

	fmt.Printf("Of %s and %s, %s is older by %d years\n", bob.name, paul.name, bp_Older.name, bp_diff)
}