我在使用Selenium Python绑定的测试代码中遇到此错误：

>           twitter_campaigns = wait.until(EC.visibility_of_element_located(By.CSS_SELECTOR, TWITTER_CAMPAIGNS))
E           TypeError: __init__() takes exactly 2 arguments (3 given)

这就是我正在执行的操作：

class TestTwitter(TestLogin, TestBuying):

    def setup(self, timeout=10):
        self.driver = webdriver.Firefox()
        self.driver.get(BASEURL)
        self.driver.implicitly_wait(timeout)

    def test_campaigns_loaded(self, timeout=10):
        self.signin_action()
        self.view_twitter_dashboard()
        self.select_brand()
        wait = WebDriverWait(self.driver, timeout)
        twitter_campaigns = wait.until(EC.visibility_of_element_located(By.CSS_SELECTOR, TWITTER_CAMPAIGNS))
        assert True == twitter_campaigns

    def teardown(self):
        self.driver.close()

所以我想知道为什么我在所有类上都没有定义__init__()方法，而是在pytest之后定义了setUp和tearDown方法，从而导致上述错误。任何想法为什么要采取3
args？