class AutoFieldMixin

def check(self, **kwargs)

    def check(self, **kwargs):
        return [
            *super().check(**kwargs),
            *self._check_primary_key(),
        ]

def contribute_to_class(self, cls, name, **kwargs)

    def contribute_to_class(self, cls, name, **kwargs):
        if cls._meta.auto_field:
            raise ValueError(
                "Model %s can't have more than one auto-generated field."
                % cls._meta.label
            )
        super().contribute_to_class(cls, name, **kwargs)
        cls._meta.auto_field = self

def deconstruct(self)

    def deconstruct(self):
        name, path, args, kwargs = super().deconstruct()
        del kwargs["blank"]
        kwargs["primary_key"] = True
        return name, path, args, kwargs

def formfield(self, **kwargs)

    def formfield(self, **kwargs):
        return None

def get_db_prep_value(self, value, connection, prepared=False)

    def get_db_prep_value(self, value, connection, prepared=False):
        if not prepared:
            value = self.get_prep_value(value)
            value = connection.ops.validate_autopk_value(value)
        return value

def validate(self, value, model_instance)

    def validate(self, value, model_instance):
        pass