@override_settings(DATABASE_ROUTERS=[AntiPetRouter()])
    def test_pseudo_empty_fixtures(self):
        new_io = StringIO()
        management.call_command('loaddata', 'pets', stdout=new_io, stderr=new_io)
        command_output = new_io.getvalue().strip()
        # No objects will actually be loaded
        self.assertEqual(command_output, "Installed 0 object(s) (of 2) from 1 fixture(s)")
A fixture can contain entries, but lead to nothing in the database;
dataset/ETHPy150Open django/django/tests/multiple_database/tests.py/FixtureTestCase.test_pseudo_empty_fixtures