Crm::isAllowDeleteFolder

public function isAllowDeleteFolder(DiskFolder $folder): bool
{
	if (!$this->isMeasureAvailable())
	{
		return true;
	}

	if ($folder->isDeleted())
	{
		return true;
	}

	static $crmFolderIds;
	if (empty($crmFolderIds))
	{
		$crmFolderIds = [];
		$crmStorageList = $this->getStorageList();
		foreach ($crmStorageList as $crmStorage)
		{
			$crmFolders = $this->getFolderList($crmStorage);
			if (is_array($crmFolders) && count($crmFolders) > 0)
			{
				foreach ($crmFolders as $crmFolder)
				{
					$crmFolderIds[] = $crmFolder->getId();
				}
			}
		}
	}

	// disallow delete Crm folder
	return (in_array($folder->getId(), $crmFolderIds) === false);
}