!9687 Modify the use case of the afterRemoval interface in the util module in...

!9687 Modify the use case of the afterRemoval interface in the util module in the docs document to become popular
Merge pull request !9687 from 毕虎/master

zh-cn/application-dev/reference/apis/js-apis-util.md

@@ -1145,7 +1145,7 @@ afterRemoval(isEvict: boolean,key: K,value: V,newValue: V): void
 **示例：**
   ```js
   let arr = [];
-  class ChildLruBuffer extends util.LruBuffer
+  class ChildLruBuffer<K, V> extends util.LruBuffer<K, V>
   {
   	constructor()
   	{