src/vs/platform/backup/electron-main/backupMainService.ts/BackupMainService/registerFolderBackup
class BackupMainService:	registerFolderBackup(folderInfo: IFolderBackupInfo): string {
		if (!this.folders.some(folder => this.backupUriComparer.isEqual(folderInfo.folderUri, folder.folderUri))) {
			this.folders.push(folderInfo);
			this.storeWorkspacesMetadata();
		}

		return join(this.backupHome, this.getFolderHash(folderInfo));
	}