namespace System.Collections.ObjectModel
{
    [DebuggerDisplay("Count = {Count}")]
    [DebuggerTypeProxy(typeof(ICollectionDebugView<?>))]
    [DefaultMember("Item")]
    public class Collection<T> : ICollection<T>, IEnumerable<T>, IList<T>, IReadOnlyCollection<T>, IReadOnlyList<T>, ICollection, IEnumerable, IList
    {
        protected virtual void SetItem(int index, T item);
    }
}