MailboxDirectoryHelper::buildTreeDirs

public function buildTreeDirs()
{
	$list = [];
	$result = [];
	$dirs = $this->getDirs();

	foreach ($dirs as $dir)
	{
		$list[$dir->getId()] = $dir;
	}

	foreach ($list as $id => $dir)
	{
		if (!empty($list[$dir->getParentId()]))
		{
			$list[$dir->getParentId()]->addChild($dir);
		}
		else
		{
			$result[$dir->getId()] = $dir;
		}
	}

	return $this->orderByDefault($result);
}