src/vs/workbench/contrib/notebook/browser/services/notebookRendererMessagingServiceImpl.ts/NotebookRendererMessagingService/receiveMessage
class NotebookRendererMessagingService:	public receiveMessage(editorId: string | undefined, rendererId: string, message: unknown): Promise<boolean> {
		if (editorId === undefined) {
			const sends = [...this.scopedMessaging.values()].map(e => e.receiveMessageHandler?.(rendererId, message));
			return Promise.all(sends).then(s => s.some(s => !!s));
		}

		return this.scopedMessaging.get(editorId)?.receiveMessageHandler?.(rendererId, message) ?? Promise.resolve(false);
	}