src/vs/workbench/services/untitled/common/untitledTextEditorModel.ts/UntitledTextEditorModel/backup
class UntitledTextEditorModel:	async backup(token: CancellationToken): Promise<IWorkingCopyBackup> {

		// Fill in content the same way we would do when
		// saving the file via the text file service
		// encoding support (hardcode UTF-8)
		const content = await this.textFileService.getEncodedReadable(this.resource, withNullAsUndefined(this.createSnapshot()), { encoding: UTF8 });

		return { content };
	}