XML : Add horizontal views (line) between menu items xml

I'm using Navigation View, tags menu and items, I would like put lines between every option. Here is my menu:

    <group android:checkableBehavior="single">      <item          android:id="@+id/nav_camera"          android:icon="@drawable/ic_menu_camera"          android:title="Import" />      <item          android:id="@+id/nav_gallery"          android:icon="@drawable/ic_menu_gallery"          android:title="Gallery" />      <item          android:id="@+id/nav_slideshow"          android:icon="@drawable/ic_menu_slideshow"          android:title="Slideshow" />      <item          android:id="@+id/nav_manage"          android:icon="@drawable/ic_menu_manage"          android:title="Tools" />  </group>    

I don't know well how works this items and why we can not put other classes of tags from XML