#### 只展开当前父级菜单
点击菜单，收起其他展开的所有菜单，保持菜单聚焦简洁。
#### Open current submenu only
Click the menu and you will see that all the other menus gets collapsed to keep the entire menu compact.
```html
Navigation One
Option 1
Option 2
Option 3
Option 4
Navigation Two
Option 5
Option 6
Option 7
Option 8
Navigation Three
Option 9
Option 10
Option 11
Option 12
```