Router::getFullPath

protected function getFullPath(string $folder = '', ?int $entityTypeId = null): string
{
	$root = $this->getRoot();
	if ($entityTypeId > 0 && isset($this->customRoots[$entityTypeId]))
	{
		$root = $this->customRoots[$entityTypeId];
	}
	return Path::combine($this->getSiteFolder(), $root, $folder) . '/';
}