using System; using System.Windows; namespace Microsoft.Windows.Shell; public class ThumbButtonInfoCollection : FreezableCollection { protected override Freezable CreateInstanceCore() { return new ThumbButtonInfoCollection(); } internal static ThumbButtonInfoCollection Empty { get { if (ThumbButtonInfoCollection.s_empty == null) { ThumbButtonInfoCollection thumbButtonInfoCollection = new ThumbButtonInfoCollection(); thumbButtonInfoCollection.Freeze(); ThumbButtonInfoCollection.s_empty = thumbButtonInfoCollection; } return ThumbButtonInfoCollection.s_empty; } } private static ThumbButtonInfoCollection s_empty; }