* When the maximum number of threads is reached and workers are busy, an event is emitted. If you want to listen to this event, use the pool's `emitter`.
*
* @typeParam Data - Type of data sent to the worker. This can only be serializable data.
* When the maximum number of threads is reached and workers are busy, an event is emitted. If you want to listen to this event, use the pool's `emitter`.
*
* @typeParam Data - Type of data sent to the worker. This can only be serializable data.