我不明白Positional Argument错误消息

Question

所以我的代码按预期执行，但是我一直遇到位置参数错误消息，我只是不理解错误。

这是我的代码

import unittest
import re
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

class test(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.get("https://foo.bar")

    def test_input_maxlength (self):
        driver = self.driver
        wait = WebDriverWait(driver, 10)
        #userInput = 'Howdy there partner long long long long long test. Howdy there partner long long long long long test.'
        userInput = 'Howdy there partner.'
        inputBoxOneXpath = wait.until(lambda driver: driver.find_element_by_xpath("//input[@type='text']"))
        inputBoxTwoXpath = wait.until(lambda driver: driver.find_element_by_xpath("//input[@class='xc-textbox']"))
        inputBoxOneXpath.clear()
        inputBoxTwoXpath.clear()
        inputBoxOneXpath.send_keys(userInput)
        wait.until(EC.visibility_of(By.CLASS_NAME, "xc-textbox"))
        if (inputBoxOneXpath.get_attribute("value") == inputBoxTwoXpath.get_attribute("value")):
            print ("Input text is mirrored.")
        else:
            print ("Input text is not mirrored, maxlength has been exceeded.")

    def tearDown(self):
        self.driver.quit

以下是我一直收到的错误消息

  File "lab.py", line 24, in test_input_maxlength
    wait.until(EC.visibility_of(By.CLASS_NAME, "xc-textbox"))
TypeError: __init__() takes 2 positional arguments but 3 were given