| ⇢ | A | Book added | |
| ⇢ | A | BookController added | |
| A | ↛ | Book removed | |
| A | ↛ | SampleRoutesCommand removed | |
| A | ↛ | BookController removed |
| ⇢ | A | Book::getReleaseDateAttribute() added | |
| ⇢ | A | Book::setReleaseDateAttribute() added | |
| ⇢ | A | BookController::createBook() added | |
| ⇢ | A | BookController::deleteBook() added | |
| A | ↛ | SampleRoutesCommand::handle() removed | |
| A | ↛ | BookController::createBook() removed | |
| A | ↛ | Book::getReleaseDateAttribute() removed | |
| A | ↛ | Book::setReleaseDateAttribute() removed | |
| A | ↛ | BookController::deleteBook() removed |