namespace System.ServiceModel
{
    public sealed class ExtensionCollection<T> : SynchronizedCollection<IExtension<T>>, ICollection<IExtension<T>>, IEnumerable, IEnumerable<IExtension<T>>, IExtensionCollection<T>
        where T, IExtensibleObject<T>
    {
        public ExtensionCollection(T owner);
    }
}