Extracts the URL from an image element on the page.

def get_image_url(self, selector, by=By.CSS_SELECTOR,
                      timeout=settings.SMALL_TIMEOUT):
        """ Extracts the URL from an image element on the page. """
        if self.timeout_multiplier and timeout == settings.SMALL_TIMEOUT:
            timeout = self.__get_new_timeout(timeout)
        return self.get_attribute(selector,
                                  attribute='src', by=by, timeout=timeout)