in src/dotnet/JetBrains.PresentationAssistant/WpfPopupWindow.cs [59:65]
protected override void AttachWindowEvents()
{
window.SizeChanged += OnWindowSizeChanged;
window.Closed += OnWindowClosed;
window.Deactivated += OnWindowDeactivated;
window.SourceInitialized += OnWindowSourceInitialized;
}