def test_app_form_neither_blplugin_and_blitem(self):
        data = {'blitem': None, 'blplugin': None}
        form = forms.BlocklistAppForm(data)
        assert not form.is_valid()
        assert 'One and only one' in str(form.errors)
dataset/ETHPy150Open mozilla/addons-server/src/olympia/blocklist/tests/test_forms.py/BlocklistFormTest.test_app_form_neither_blplugin_and_blitem/original