Avalonia/tests/BuildTests/BuildTests/MainWindow.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:BuildTests"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        x:Class="BuildTests.MainWindow"
        Icon="/Assets/avalonia-logo.ico"
        Title="BuildTests">
  <local:MainView />
</Window>