AndroidAPS/app/src/main/res/layout/bgsource_fragment.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingTop="2dp"
    tools:context="info.nightscout.androidaps.plugins.source.BGSourceFragment">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/bgsource_recyclerview"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

        </androidx.recyclerview.widget.RecyclerView>

    </LinearLayout>

</FrameLayout>