def METHOD_NAME(self, event_type=None) -> dict:
    if self.es is None:
        return {}
    pattern = "logstash-*"
    if event_type is not None:
        pattern = "logstash-%s-*" % event_type
    resp = self.es.indices.get_mapping(index=pattern)
    fields = []
    for k in resp:
        fields.extend(self._walk_properties(d=resp[k].METHOD_NAME("mappings", {}).METHOD_NAME("properties", {})))
    return {
        "fields": sorted(list(set(fields)))
    }