This application uses Python 3 and Django 3.0.3. It contains a Books module for managing book entities. Your job is to finish an implementation of the CRUD functionality using CBV.

Please implement four class-based views (CBV) and mixins for them, so all unit tests will start passing. Also use Django's messages framework to add success/error messages.

Your implementation should load book details data for given isbn parameter. If book for passed isbn doesn't exist, user should be redirected to a '/books/' default route (BookListView: books:index).

Your implementation should populate the form fields with a book's details. After successful submission user should be redirected to the page for the created book (BookDetailView: books:detail). And do not forget to add a validator to check a isbn, it can be separated into its parts with hyphens, so isbn may only contain digits and hyphens.

Your implementation should populate the form fields with a book's details for passed isbn parameter. If book for passed isbn doesn't exist, user should be redirected to a '/books/' default route (BookListView: books:index). After successful submission user should be redirected to the page for the edited book (BookDetailView: books:detail).

Your implementation should delete a book for given isbn parameter. If book for passed isbn doesn't exist, user should be redirected to a '/books/' default route (BookListView: books:index). After the book is deleted, the user should be redirected to a list of books (BookListView: books:index).

You shouldn't modify the unit tests, just complete the CBVs and mixins to make the unit tests run as expected.

To execute all unit tests, use:

pip install -q -e . && nosetests

• Add nose for being able to run the unit tests
• Check if unit tests run (with or without nose)
• Add 404, 403 or 500 error pages