Add cell tag

Author: VeckoTheGecko

advanced/backends/intro-backends.ipynb

@@ -153,7 +153,11 @@
    "cell_type": "code",
    "execution_count": null,
    "id": "12",
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "raises-exception"
+    ]
+   },
    "outputs": [],
    "source": [
     "xr.tutorial.open_dataset(\"air_temperature\", engine=\"pydap\")"