PowerToys/src/core/Microsoft.PowerToys.Settings.UI/Controls/DummyUserControl.xaml

<UserControl
    x:Class="Microsoft.PowerToys.Settings.UI.Controls.DummyUserControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Microsoft.PowerToys.Settings.UI.Controls"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:winui="using:Microsoft.UI.Xaml.Controls"
    mc:Ignorable="d"
    d:DesignHeight="300"
    d:DesignWidth="400">

    <Grid>
        <winui:NavigationView>
            <winui:NavigationView.MenuItems>
                <winui:NavigationViewItem Content="1" Icon="Home" />
                <winui:NavigationViewItem Content="2" Icon="Home" />
                <winui:NavigationViewItem Content="3" Icon="Home" />
                <winui:NavigationViewItem Content="4" Icon="Home" />
            </winui:NavigationView.MenuItems>
            <Frame x:Name="ContentFrame" Padding="12,0,12,24" IsTabStop="True" />
        </winui:NavigationView>
    </Grid>
</UserControl>