pub unsafe extern "C" fn rd_kafka_conf_set_dr_cb(
conf: *mut rd_kafka_conf_t,
dr_cb: Option<unsafe extern "C" fn(rk: *mut rd_kafka_t, payload: *mut c_void, len: usize, err: rd_kafka_resp_err_t, opaque: *mut c_void, msg_opaque: *mut c_void)>,
)