diff --git a/.vitepress/utils.ts b/.vitepress/utils.ts
index dc8a2a788..961ad414c 100644
--- a/.vitepress/utils.ts
+++ b/.vitepress/utils.ts
@@ -1,12 +1,3 @@
-export function groupBy<T, K extends keyof any>(
-  arr: T[],
-  key: (i: T) => K
-): Record<K, T[]> {
-  return arr.reduce(
-    (groups, item) => {
-      ;(groups[key(item)] ||= []).push(item)
-      return groups
-    },
-    {} as Record<K, T[]>
-  )
-}
+const arr = [{name: 'Alice', age: 30}, {name: 'Bob', age: 25}, {name: 'Charlie', age: 30}];
+const groupedByAge = groupBy(arr, item => item.age);
+// groupedByAge is now equal to {25: [{name: 'Bob', age: 25}], 30: [{name: 'Alice', age: 30}, {name: 'Charlie', age: 30}]}