Adding a book with a set of covers (option 3)

The create_book function is responsible for creating a Book model record and associated BookCover records. The list of covers is passed in the validate_data dictionary under the key covers. A code review should be conducted: ensure that the logic is implemented correctly, check for potential issues with performance or atomicity of operations. Verify that cover objects are created properly, consider whether using the objs variable makes sense, if replacing individual create calls with bulk_create is appropriate, and whether additional checks or wrapping in a transaction are necessary.