code: def assert_screenshot(self, filename, threshold=0, exclude_elements=[], force=False):
          
          VisualTest(self.driver_wrapper, force).assert_screenshot(self.web_element, filename, self.__class__.__name__,
                                                                   threshold, exclude_elements)
docs: Assert that a screenshot of the element is the same as a screenshot on disk, within a given threshold.
  
          :param filename: the filename for the screenshot, which will be appended with ``.png``
          :param threshold: percentage threshold for triggering a test failure (value between 0 and 1)
          :param exclude_elements: list of WebElements, PageElements or element locators as a tuple (locator_type,
                                   locator_value) that must be excluded from the assertion
          :param force: if True, the screenshot is compared even if visual testing is disabled by configuration