src/vs/workbench/services/workingCopy/common/untitledFileWorkingCopy.ts/UntitledFileWorkingCopy/backup
class UntitledFileWorkingCopy:	async backup(token: CancellationToken): Promise<IWorkingCopyBackup> {
		let content: VSBufferReadableStream | undefined = undefined;

		// Make sure to check whether this working copy has been
		// resolved or not and fallback to the initial value -
		// if any - to prevent backing up an unresolved working
		// copy and loosing the initial value.
		if (this.isResolved()) {
			content = await raceCancellation(this.model.snapshot(token), token);
		} else if (this.initialContents) {
			content = this.initialContents.value;
		}

		return { content };
	}