def METHOD_NAME(self, backend_settings=None, backends=None):
    """
    Performs the purge of all the URLs in this batch
    This method takes two optional keyword arguments: backend_settings and backends
    - backend_settings can be used to override the WAGTAILFRONTENDCACHE setting for
      just this call
    - backends can be set to a list of backend names. When set, the invalidation request
      will only be sent to these backends
    """
    purge_urls_from_cache(self.urls, backend_settings, backends)