src/vs/workbench/contrib/tasks/browser/abstractTaskService.ts/AbstractTaskService/createTasksDotOld
class AbstractTaskService:	private async createTasksDotOld(folder: IWorkspaceFolder): Promise<[URI, URI] | undefined> {
		const tasksFile = folder.toResource('.vscode/tasks.json');
		if (await this.fileService.exists(tasksFile)) {
			const oldFile = tasksFile.with({ path: `${tasksFile.path}.old` });
			await this.fileService.copy(tasksFile, oldFile, true);
			return [oldFile, tasksFile];
		}
		return undefined;
	}