The copyWith method is used to clone a modddel with different values. The resulting modddel is completely independent from the cloned one, and is validated separately.
/// This is our Modddel
final book = Book(
id: '#1',
title: 'The adventures of Dash',
);
final otherBook = book.copyWith(
title: 'The mistery of Dash',
);
The copyWith method supports assigning null to a value.
