src/vs/platform/backup/electron-main/backupMainService.ts/BackupMainService/getFolderHash
class BackupMainService:	protected getFolderHash(folderUri: URI): string {
		let key: string;

		if (folderUri.scheme === Schemas.file) {
			// for backward compatibility, use the fspath as key
			key = isLinux ? folderUri.fsPath : folderUri.fsPath.toLowerCase();
		} else {
			key = folderUri.toString().toLowerCase();
		}

		return createHash('md5').update(key).digest('hex');
	}