def test_has_permission_default_read(self):
        self.backend.default_read = ['everyone', 'authenticated']
        self.backend.default_write = []
        perms = self.backend.allowed_permissions('anypkg')
        self.assertEqual(perms, {Everyone: ('read',),
                                 Authenticated: ('read',)})
If no user/group permissions on a package, use default_read
dataset/ETHPy150Open mathcamp/pypicloud/tests/test_access_backends.py/TestBaseBackend.test_has_permission_default_read