void(* as_pipe_listener)(void *udata, as_event_loop *event_loop)
void(* as_async_value_listener)(as_error *err, as_val *val, void *udata, as_event_loop *event_loop)
void(* as_async_write_listener)(as_error *err, void *udata, as_event_loop *event_loop)
void(* as_async_record_listener)(as_error *err, as_record *record, void *udata, as_event_loop *event_loop)
void(* as_async_info_listener)(as_error *err, char *response, void *udata, as_event_loop *event_loop)