Waits for an element to appear in the HTML of a page.
            The element must be visible (it cannot be hidden).

def wait_for_element_visible(self, selector, by=By.CSS_SELECTOR,
                                 timeout=settings.LARGE_TIMEOUT):
        """ Waits for an element to appear in the HTML of a page.
            The element must be visible (it cannot be hidden). """
        if page_utils.is_xpath_selector(selector):
            by = By.XPATH
        if page_utils.is_link_text_selector(selector):
            selector = page_utils.get_link_text_from_selector(selector)
            by = By.LINK_TEXT
        return page_actions.wait_for_element_visible(
            self.driver, selector, by, timeout)