Calendar::addEvent

public function addEvent($event): Calendar
{
	if (is_null($event))
	{
		return $this;
	}

	$events = array_map(function ($eventToResolve) {
		if (! is_callable($eventToResolve)) {
			return $eventToResolve;
		}
		$newEvent = new Event(Helper::getUniqId());

		$eventToResolve($newEvent);

		return $newEvent;
	}, is_array($event) ? $event : [$event]);

	$this->events = array_merge($this->events, $events);

	return $this;
}