RecyclerView is below toolbar
<p><strong>Problem:</strong> I have a <code>RecyclerView</code> and a <code>Toolbar</code> in a <code>CoordinatorLayout</code>.
The <code>RecyclerView</code> is below the <code>Toolbar</code> but it should not.</p>

<p><a href="https://i.stack.imgur.com/QvnvD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QvnvD.png" alt="enter image description here"></a> </p>

<p><strong>Question:</strong> How can I achieve that the <code>RecyclerView</code> and the <code>Toolbar</code> have one border?</p>

<p><strong>activity_main.xml</strong></p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:fitsSystemWindows="true"&gt;

    &lt;android.support.design.widget.AppBarLayout
        android:id="@+id/appBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"&gt;

    &lt;include
        android:id="@+id/toolbar_main"
        layout="@layout/toolbar"&gt;&lt;/include&gt;

    &lt;/android.support.design.widget.AppBarLayout&gt;

    &lt;FrameLayout
        android:id="@+id/maschinelistcontainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent" /&gt;

&lt;/android.support.design.widget.CoordinatorLayout&gt;
</code></pre>

<p><strong>maschine_fragment.xml</strong></p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"&gt;

    &lt;android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipToPadding="false"
        android:scrollbars="vertical" /&gt;

&lt;/LinearLayout&gt;
</code></pre>