Interface Accepting Address of the Variable in Golang

package main

import "fmt"

type Book struct {
	author, title string
}

type Magazine struct {
	title string
	issue int
}

func (b *Book) Assign(n, t string) {
	b.author = n
	b.title = t
}
func (b *Book) Print() {
	fmt.Printf("Author: %s, Title: %s\n", b.author, b.title)
}

func (m *Magazine) Assign(t string, i int) {
	m.title = t
	m.issue = i
}
func (m *Magazine) Print() {
	fmt.Printf("Title: %s, Issue: %d\n", m.title, m.issue)
}

type Printer interface {
	Print()
}

func main() {
	var b Book                                 // Declare instance of Book
	var m Magazine                             // Declare instance of Magazine
	b.Assign("Jack Rabbit", "Book of Rabbits") // Assign values to b via method
	m.Assign("Rabbit Weekly", 26)              // Assign values to m via method

	var i Printer // Declare variable of interface type
	fmt.Println("Call interface")
	i = &b    // Method has pointer receiver, interface does not
	i.Print() // Show book values via the interface
	i = &m    // Magazine also satisfies shower interface
	i.Print() // Show magazine values via the interface
}