make IsOpenProperty on flyoutbase public.
@ -22,7 +22,7 @@ namespace Avalonia.Controls.Primitives
/// <summary>
/// Defines the <see cref="IsOpen"/> property
/// </summary>
private static readonly DirectProperty<FlyoutBase, bool> IsOpenProperty =
public static readonly DirectProperty<FlyoutBase, bool> IsOpenProperty =
AvaloniaProperty.RegisterDirect<FlyoutBase, bool>(nameof(IsOpen),
x => x.IsOpen);