def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
def test_default_group(self):
        # It exists
        self.assertTrue(Group.objects.filter(name='Default').count() == 1)

        # Verify that all new users are assigned to default group
        u = User.objects.create_user(username="default_user")
        u.refresh_from_db()
        self.assertTrue(u.groups.filter(name='Default').count() == 1)