add example to group sort warning

content/v2.0/reference/flux/stdlib/built-in/transformations/group.md

@@ -37,6 +37,12 @@ group()
 `group()` does not guarantee the sort order of output records.
 To ensure data is sorted correctly, use [`sort()`](/v2.0/reference/flux/stdlib/built-in/transformations/sort/)
 after `group()`.
+
+```js
+data
+  |> group()
+  |> sort(columns: ["_time"])
+```
 {{% /warn %}}
 
 ## Parameters