namespace System.Activities.Presentation.Model
{
    [DefaultMember("Item")]
    public abstract class ModelItemDictionary : ModelItem, ICollection<KeyValuePair<ModelItem, ModelItem>>, IDictionary<ModelItem, ModelItem>, IEnumerable, IEnumerable<KeyValuePair<ModelItem, ModelItem>>, ICollection, IDictionary, INotifyCollectionChanged
    {
        public abstract ModelItem Add(object key, object value);
    }
}