src/vs/platform/backup/electron-main/backupMainService.ts/BackupMainService/hasBackups
class BackupMainService:	private hasBackups(backupLocation: IWorkspaceBackupInfo | IEmptyWindowBackupInfo | IFolderBackupInfo): Promise<boolean> {
		let backupPath: string;

		// Empty
		if (isEmptyWindowBackupInfo(backupLocation)) {
			backupPath = join(this.backupHome, backupLocation.backupFolder);
		}

		// Folder
		else if (isFolderBackupInfo(backupLocation)) {
			backupPath = join(this.backupHome, this.getFolderHash(backupLocation));
		}

		// Workspace
		else {
			backupPath = join(this.backupHome, backupLocation.workspace.id);
		}

		return this.doHasBackups(backupPath);
	}