Avalonia/src/Avalonia.Base/VisualTree/IVisualWithRoundRectClip.cs

using System;
using System.ComponentModel;

namespace Avalonia.VisualTree
{
    internal interface IVisualWithRoundRectClip
    {
        /// <summary>
        /// Gets a value indicating the corner radius of control's clip bounds
        /// </summary>
        CornerRadius ClipToBoundsRadius { get; }
    }
}