src/vs/platform/backup/electron-main/backupMainService.ts/BackupMainService/registerWorkspaceBackupSync
class BackupMainService:	registerWorkspaceBackupSync(workspaceInfo: IWorkspaceBackupInfo, migrateFrom?: string): string {
		if (!this.workspaces.some(workspace => workspaceInfo.workspace.id === workspace.workspace.id)) {
			this.workspaces.push(workspaceInfo);
			this.saveSync();
		}

		const backupPath = this.getBackupPath(workspaceInfo.workspace.id);

		if (migrateFrom) {
			this.moveBackupFolderSync(backupPath, migrateFrom);
		}

		return backupPath;
	}