Book.php

<?php

class Book implements BookInterface {
    public function open()
    {
        var_dump('opening the paper book.');
    }
    public function turnPage()
    {
        var_dump('turning the page of the paper book.');
    }
} 

BookInterface.php

<?php

interface BookInterface {
  
    public function open();
  
    public function turnPage();
  
}

index.php

<?php 

class Person {
  
  public function read(BookInterface $book)
  {
    $book->open();
    $book->turnPage();
  }
    
}

(new Person)->read(new Book);