Android NavigationView menu group divider [duplicate]

Android support design library provide NavigationView:

 <android.support.design.widget.NavigationView
    ...
    app:menu="@menu/navigation_drawer_items" />

menu/navigation_drawer_items:

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <group android:checkableBehavior="single">
        <item .../>
        ...
    </group>

    <group android:checkableBehavior="single">
        <item .../>
        ...
    </group>

</menu>

How to add divider, separator or space between groups (like on picture)?

Just give a unique id to each group. It will create a separator automatically.

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <group android:id="@+id/group_feature"
        android:checkableBehavior="single">
        <item android:id="@+id/navdrawer_item_map"
            android:checked="true"
            android:icon="@drawable/ic_drawer_map"
            android:title="@string/navdrawer_item_map"/>

    </group>
    <group android:id="@+id/group_settings"
        android:checkableBehavior="single">
        <item android:id="@+id/navdrawer_item_settings"
            android:icon="@drawable/ic_drawer_settings"
            android:title="@string/navdrawer_item_settings"/>

    </group>
</menu>

you do something like this.

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <group android:checkableBehavior="single">
        <item
            android:id="@+id/nav_home"
            android:icon="@drawable/ic_dashboard"
            android:title="Home" />
        <item
            android:id="@+id/nav_messages"
            android:icon="@drawable/ic_event"
            android:title="Messages" />
        <item
            android:id="@+id/nav_friends"
            android:icon="@drawable/ic_headset"
            android:title="Friends" />
        <item
            android:id="@+id/nav_discussion"
            android:icon="@drawable/ic_forum"
            android:title="Discussion" />
    </group>

    <item android:title="Sub items">
        <menu>
            <item
                android:icon="@drawable/ic_dashboard"
                android:title="Sub item 1" />
            <item
                android:icon="@drawable/ic_forum"
                android:title="Sub item 2" />
        </menu>
    </item>

</menu>

this code is taken from the Design Library example app made by Chris Barnes https://github.com/chrisbanes/cheesesquare