(fields) defined in the `response_model`. If you returned an object
                    that contains an attribute `password` but the `response_model` does
                    not include that field, the JSON sent to the client would not have
                    that `password`.
                * Validation: whatever you return will be serialized with the

            # 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.
            # By being a new field, no inheritance will be passed as is. A new model