src/vs/workbench/contrib/notebook/browser/notebookRendererMessagingServiceImpl.ts/NotebookRendererMessagingService/getScoped
class NotebookRendererMessagingService:	public getScoped(editorId: string): IScopedRendererMessaging {
		const existing = this.scopedMessaging.get(editorId);
		if (existing) {
			return existing;
		}

		const messaging: IScopedRendererMessaging = {
			postMessage: (rendererId, message) => this.postMessage(editorId, rendererId, message),
			dispose: () => this.scopedMessaging.delete(editorId),
		};

		this.scopedMessaging.set(editorId, messaging);
		return messaging;
	}