def test_m2m_export(self):
        cat1 = Category.objects.create(name='Cat 1')
        cat2 = Category.objects.create(name='Cat 2')
        self.book.categories.add(cat1)
        self.book.categories.add(cat2)

        dataset = self.resource.export(Book.objects.all())
        self.assertEqual(dataset.dict[0]['categories'],
                         (cat1.pk, cat2.pk) % '%d,%d')
dataset/ETHPy150Open django-import-export/django-import-export/tests/core/tests/resources_tests.py/ModelResourceTest.test_m2m_export/swapped operands of `%`