src/vs/workbench/services/textfile/browser/browserTextFileService.ts/BrowserTextFileService/onBeforeShutdown
class BrowserTextFileService:	private onBeforeShutdown(): boolean {
		if (this.files.models.some(model => model.hasState(TextFileEditorModelState.PENDING_SAVE))) {
			return true; // files are pending to be saved: veto (as there is no support for long running operations on shutdown)
		}

		return false;
	}