the client doesn't have to provide it.

                But when using `Item` for output, for a response body, `tags` is always
                available because it has a default value, even if it's just an empty
                list. So, the client should be able to always expect it.

                In this case, there would be two different schemas, one for input and

            )
            # Create a clone of the field, so that a Pydantic submodel is not returned
            # as is just because it's an instance of a subclass of a more limited class
            # e.g. UserInDB (containing hashed_password) could be a subclass of User
            # that doesn't have the hashed_password. But because it's a subclass, it
            # would pass the validation and be returned as is.