HandyControl/src/Shared/HandyControl_Shared/Controls/Base/HeaderedSimpleItemsControl.cs

using System.Windows;

namespace HandyControl.Controls
{
    public class HeaderedSimpleItemsControl : SimpleItemsControl
    {
        public static readonly DependencyProperty HeaderProperty = DependencyProperty.Register(
            "Header", typeof(object), typeof(HeaderedSimpleItemsControl), new PropertyMetadata(default(object)));

        public object Header
        {
            get => GetValue(HeaderProperty);
            set => SetValue(HeaderProperty, value);
        }
    }
}