function Book(title, price) {
  this.title = title;
  this.price = price;
  this.printTitle = () => console.log(this.title);
}
function BookPrototype(prototype) {
  this.prototype = prototype;
  this.clone = () => {
    let book = new Book();
    book.title = prototype.title;
    book.price = prototype.price;
    
    return book;
  };
}
let sampleBook = new Book(‘JavaScript’, 15);
let prototype = new BookPrototype(sampleBook);
let book = prototype.clone();
book.printTitle();