src/vs/platform/backup/electron-main/backupMainService.ts/BackupMainService/prepareNewEmptyWindowBackup
class BackupMainService:	private prepareNewEmptyWindowBackup(): IEmptyWindowBackupInfo {

		// We are asked to prepare a new empty window backup folder.
		// Empty windows backup folders are derived from a workspace
		// identifier, so we generate a new empty workspace identifier
		// until we found a unique one.

		let emptyWorkspaceIdentifier = createEmptyWorkspaceIdentifier();
		while (this.emptyWindows.some(emptyWindow => !!emptyWindow.backupFolder && this.backupPathComparer.isEqual(emptyWindow.backupFolder, emptyWorkspaceIdentifier.id))) {
			emptyWorkspaceIdentifier = createEmptyWorkspaceIdentifier();
		}

		return { backupFolder: emptyWorkspaceIdentifier.id };
	}