src/vs/platform/backup/electron-main/backupMainService.ts/BackupMainService/unregisterEmptyWindowBackupSync
class BackupMainService:	unregisterEmptyWindowBackupSync(backupFolder: string): void {
		const index = this.emptyWindows.findIndex(emptyWindow => !!emptyWindow.backupFolder && this.backupPathComparer.isEqual(emptyWindow.backupFolder, backupFolder));
		if (index !== -1) {
			this.emptyWindows.splice(index, 1);
			this.saveSync();
		}
	}