Return the dictionary of OpenAPI field attributes for a dump_only field.

        :param Field field: A marshmallow field.
        :rtype: dict

def field2read_only(self, field, **kwargs):
        """Return the dictionary of OpenAPI field attributes for a dump_only field.

        :param Field field: A marshmallow field.
        :rtype: dict
        """
        attributes = {}
        if field.dump_only:
            attributes["readOnly"] = True
        return attributes