📝 **Task:** Define @dataclass \`Book\` with fields title (str), pages (int), in_stock (bool, default True). Create Book("Python 101", 250) and print it. Expected: Book(title='Python 101', pages=250, in_stock=True) 📋 Edit the starter code below. Tests run automatically. 💡 **Hint:** Re-read the theory if you get stuck.