def METHOD_NAME(self):
    """Non-default database engine backend shouldn't allow to read from
    disk."""
    # we're using a different backend than what's used for normal templates
    # because we don't want to allow users to render what they shouldn't
    template = "{% include 'base.html' %}"
    data = dict()
    with self.assertRaises(TemplateDoesNotExist):
        # with this test, we're confirming that `db_backend`, a default for
        # EmailTemplate, is unable to reach `base.html` file
        EmailTemplate.render_template(template, data)
    # this must work, because we're using Django-main template engine
    EmailTemplate.render_template(template, data, default_engine="django")