def METHOD_NAME(self):
    # should set the cookie for the correct language.
    self.client.get("/?lang=zh-CN", follow=True)
    response = self.client.get("/", follow=True)
    self.assertRedirects(response, "/zh-CN/")
    self.client.get("/?lang=en-US", follow=True)
    response = self.client.get("/", follow=True)
    self.assertRedirects(response, "/en-US/")