Is there an event that fires when a System is activated/added?

[NitroPlum]

I know there is an @:add event for when components are added to the system, but what about one that runs when the entire system is re-activated?

[player-03]

class MySystem extends System {
	public function new() {
		onActivate.add(() -> trace("MySystem activated"));
		onDeactivate.add(() -> trace("MySystem deactivated"));
	}
}

Also note that once activated, the system will receive any pending @:add events all at once. This is meant to help you worry less about initialization order. You'll get the event regardless of whether the entity or the system is created first.