how to structure this piece of code out…

private Author author;

private String isbn, title;

private int pages;

public int compareTo(Book another)

The compareTo method that compares the author first, title second, pages third, and lastly isbn of the book

Specified by:

compareTo in interface Comparable<Book>

Parameters:

another - The book object that is being compared to

Throws:

IllegalArgumentException - if the parameter is null

public int compareTo(Book another){
if(another == null){
throw new IllegalArgumentException();
}
if(this.author.compareTo(another.author) == 0){
if(this.title.compareTo(another.title) == 0) {
if (this.pages.compareTo(another.pages) == 0)
return this.isbn.compareTo(another.isbn);
}else{
return this.pages.compareTo(another.pages)
}else{
return this.title.compareTo(another.title);
}
}else{
return this.author.compareTo(another.author);
}