Function librdkafka_sys::rd_kafka_conf_set_stats_cb

pub unsafe extern fn rd_kafka_conf_set_stats_cb(conf: *mut rd_kafka_conf_t,
                                                stats_cb: Option<unsafe extern fn(rk: *mut rd_kafka_t, json: *mut c_char, json_len: size_t, opaque: *mut c_void) -> c_int>)