def abstract_target_url(self, symbol):
    """
    Generates a target url for a frame where :param:``symbol`` is used in place
    of the frame number. This is often used to generate wildcard target urls.
    """
    if not self.target_url_base.endswith("/"):
        base = self.target_url_base + "/"
    else:
        base = self.target_url_base

    return "{}{}{}{}".format(
        base, self.name_prefix, symbol, self.name_suffix
    )