namespace System.Collections.Generic
{
    [DebuggerDisplay("Count = {Count}")]
    [DebuggerTypeProxy(typeof(IDictionaryDebugView<?, ?>))]
    [DefaultMember("Item")]
    public class SortedDictionary<TKey, TValue> : ICollection<KeyValuePair<TKey, TValue>>, IDictionary<TKey, TValue>, IEnumerable, IEnumerable<KeyValuePair<TKey, TValue>>, IReadOnlyCollection<KeyValuePair<TKey, TValue>>, IReadOnlyDictionary<TKey, TValue>, ICollection, IDictionary
    {
        [DebuggerDisplay("Count = {Count}")]
        [DebuggerTypeProxy(typeof(DictionaryKeyCollectionDebugView<?, ?>))]
        public sealed class KeyCollection : ICollection<TKey>, IEnumerable, IEnumerable<TKey>, IReadOnlyCollection<TKey>, ICollection
        {
            public KeyCollection(SortedDictionary<TKey, TValue> dictionary);
        }
    }
}