pub unsafe extern "C" fn rd_kafka_conf_set_throttle_cb(
    conf: *mut rd_kafka_conf_t,
    throttle_cb: Option<unsafe extern "C" fn(rk: *mut rd_kafka_t, broker_name: *const c_char, broker_id: i32, throttle_time_ms: c_int, opaque: *mut c_void)>
)