python if __name__ ==“ __main__”：IndentationError：预期为缩进块

我使用PyCharm右键单击Run'hello'或使用shell运行python hello.py，都返回以下错误：

    if __name__ == "__main__":
                             ^ 
IndentationError: expected an indented block

下面的代码是从https://selenium-python.readthedocs.io/getting-started.html复制的

import unittest
from selenium import webdriver
from selenium.webdriver.common.keys import Keys


class TestHello(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome(
            "D:\\Softwares\\selenium\\ChromeDriver 83.0.4103.39\\chromedriver_win32\\chromedriver.exe")

    def test_pick_goods(self):
        driver = self.driver
        driver.get("http://www.python.org")
        self.assertIn("Python", driver.title)
        elem = driver.find_element_by_name("q")
        elem.send_keys("pycon")
        elem.send_keys(Keys.RETURN)
        assert "No results found." not in driver.page_source
        print("-----last line----")

    def tearDown(self):
        #self.driver.close()


if __name__ == "__main__":
    unittest.main()

如果name ==“ main ”，我使用了制表符或四个空格，但两者都无效。