Read property of class returned from factory method: The getter 'name' isn't defined for the type 'Future'

Question

how to read getter variable when it is returned from factory method? I have a class names Book like this

class Book {
  final String _name;
  String get name => _name;

  Program(this._name);

  factory Program.fromJson(List<dynamic> json) {
    return Program(
      json[0]['book_name'],
    );
  }
}

} and I'm fetchings book from api like this

Future<Book> fetchBook() async {
    final response =
        await http.get('http://book.com');

    if (response.statusCode == 200) {
      return Book.fromJson(json.decode(response.body));
    } else {
      throw Exception('Failed to load book');
    }
  }

and I'm calling this method like this

book = fetchBook();
print(book.name)

but getting this error

The getter 'name' isn't defined for the type 'Future<Book>'.
Try importing the library that defines 'name', correcting the name to the name of an existing getter, or defining a getter or field named 'name'.

How get name of the book?