src/vs/workbench/services/workingCopy/electron-sandbox/workingCopyBackupService.ts/NativeWorkingCopyBackupService/registerListeners
class NativeWorkingCopyBackupService:	private registerListeners(): void {

		// Lifecycle: ensure to prolong the shutdown for as long
		// as pending backup operations have not finished yet.
		// Otherwise, we risk writing partial backups to disk.
		this.lifecycleService.onWillShutdown(event => event.join(this.joinBackups(), 'join.workingCopyBackups'));
	}