fix streamz reference notebook (#6980)

examples/reference/panes/Streamz.ipynb

@@ -17,15 +17,21 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The ``Streamz`` pane renders [streamz](https://github.com/python-streamz/streamz) Stream objects emitting arbitrary objects, unlike the ``DataFrame`` pane which specifically handles streamz DataFrame and Series objects and exposes various formatting objects.\n",
+    "The ``Streamz`` pane renders [Streamz](https://streamz.readthedocs.io/en/latest/) Stream objects emitting arbitrary objects, unlike the ``DataFrame`` pane which specifically handles streamz DataFrame and Series objects and exposes various formatting objects.\n",
+    "\n",
+    "<div class=\"alert alert-warning\">\n",
+    "\n",
+    "If you are not already a user of the Streamz library, we recommend using functionality from the Param and Panel ecosystem, such as [reactive expressions](https://param.holoviz.org/user_guide/Reactive_Expressions.html), [generator functions](https://param.holoviz.org/user_guide/Generators.html) and/ or *periodic callbacks*. We find these features to be more robustly supported.\n",
+    "\n",
+    "</div>\n",
     "\n",
     "#### Parameters:\n",
     "\n",
     "For details on other options for customizing the component see the [layout](../../how_to/layout/index.md) and [styling](../../how_to/styling/index.md) how-to guides.\n",
     "\n",
     "* **``always_watch``** (boolean, default=False): Whether to watch the stream even when not displayed.\n",
     "* **``object``** (streamz.Stream): The streamz.Stream object being watched\n",
-    "* **``rate_limit``** (float, default=0.1): The minimum interval between events.\n",
+    "* **``rate_limit``** (float, default=0.1): The minimum interval between events in seconds.\n",
     "\n",
     "___"
    ]
@@ -80,6 +86,22 @@
     "pn.state.add_periodic_callback(emit_count, period=100, count=9);"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Lets reset the pane"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "source.emit(1)"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -105,11 +127,11 @@
     "    return alt.Chart(pd.concat(data).reset_index()).mark_line().encode(\n",
     "        x='index',\n",
     "        y='y',\n",
-    "    )\n",
+    "    ).properties(width=\"container\")\n",
     "\n",
     "altair_stream = df.cumsum().stream.sliding_window(50).map(line_plot)\n",
     "\n",
-    "altair_pane = pn.pane.Streamz(altair_stream, height=350, always_watch=True)\n",
+    "altair_pane = pn.pane.Streamz(altair_stream, height=350, sizing_mode=\"stretch_width\", always_watch=True)\n",
     "\n",
     "for i in range(100):\n",
     "    df.emit(pd.DataFrame({'y': [np.random.randn()]}, index=pd.DatetimeIndex([datetime.now()])))\n",