src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts/BackLayerWebView/_updatePreloads
class BackLayerWebView:	private _updatePreloads(resources: IControllerPreload[]) {
		if (!this.webview) {
			return;
		}

		const mixedResourceRoots = [
			...(this.localResourceRootsCache || []),
			...this.rendererRootsCache,
			...(this._currentKernel ? [this._currentKernel.localResourceRoot] : []),
		];

		this.webview.localResourcesRoot = mixedResourceRoots;

		this._sendMessageToWebview({
			type: 'preload',
			resources: resources,
		});
	}