src/vs/workbench/services/workingCopy/common/workingCopyBackupService.ts/WorkingCopyBackupServiceImpl/doDiscardBackup
class WorkingCopyBackupServiceImpl:	private async doDiscardBackup(backupResource: URI, token?: CancellationToken): Promise<void> {
		const model = await this.ready;
		if (token?.isCancellationRequested) {
			return;
		}

		return this.ioOperationQueues.queueFor(backupResource).queue(async () => {
			if (token?.isCancellationRequested) {
				return;
			}

			// Delete backup file ignoring any file not found errors
			await this.deleteIgnoreFileNotFound(backupResource);

			//
			// Update model
			//
			// Note: not checking for cancellation here because a successful
			// delete of the backup file should be noted in the model to
			// prevent the model being out of sync with the backup file
			model.remove(backupResource);
		});
	}