-post_delete.connect(update_index, Author)
-post_delete.connect(update_index, BookStub)
-post_save.connect(update_index, Author)
-post_save.connect(update_index, BookStub)
+ post_delete.connect(update_index, Author)
+ post_delete.connect(update_index, BookStub)
+ post_save.connect(update_index, Author)
+ post_save.connect(update_index, BookStub)