extra for 'extra', can_delete for 'can_delete', can_order for 'can_order', fields for 'fields', exclude for 'exclude', min_num for 'min_num', max_num for 'max_num', widgets for 'widgets', validate_min for 'validate_min', validate_max for 'validate_max', localized_fields for 'localized_fields', labels for 'labels', help_texts for 'help_texts', and error_messages for 'error_messages'. call the function modelformset_factory with 2 arguments: model and unpacked dictionary kwargs, substitute the result for FormSet.
FormSet = modelformset_factory ( model , ** kwargs )