Preset::getInstance

static function getInstance(?int $id = null): Preset
{
	if (isset(static::$instances[$id]))
	{
		return static::$instances[$id];
	}

	$instance = new static();
	if (!$id)
	{
		return $instance;
	}
	$loadResult = $instance->load($id);
	if (!$loadResult->isSuccess())
	{
		return $instance;
	}

	static::$instances[$id] = $instance;

	return $instance;
}