text: def test_valid_login(mobile_web_driver):
      mobile_web_driver.get('https://www.saucedemo.com/v1')
  
      mobile_web_driver.find_element_by_id('user-name').send_keys('locked_out_user')
      mobile_web_driver.find_element_by_id('password').send_keys('secret_sauce')
      mobile_web_driver.find_element_by_css_selector('.btn_action').click()
  
      assert mobile_web_driver.find_element_by_css_selector('.error-button').is_displayed()
  