Mail::getFolderList

public function getFolderList($storage): array
{
	if (
		$storage instanceof DiskStorage
		&& $storage->getId() > 0
	)
	{
		if (
			!isset($this->folderList[$storage->getId()])
			|| empty($this->folderList[$storage->getId()])
		)
		{
			$this->folderList[$storage->getId()] = [];
			if ($this->isMeasureAvailable())
			{
				$this->folderList[$storage->getId()][] = $storage->getRootObject();
			}
		}

		return $this->folderList[$storage->getId()];
	}

	return [];
}