IEnumrable And IEnumrator

public class MyClass
{
    // ...
}

public class MyClassCollection : IEnumerator, IEnumerator<MyClass>, IEnumerable, IEnumerable<MyClass>
{
    private int index;
    private List<MyClass> collection;

    public MyClassCollection()
    {
        collection = new List<MyClass>();
    }
    public MyClassCollection(IEnumerable<MyClass> items)
    {
        index = -1;
        collection = new List<MyClass>(items);
    }

    public MyClass this[int index]
    {
        get { return collection[index]; }
        set { collection[index] = value; }
    }

    public void Add(MyClass item)
    {
        collection.Add(item);
    }
    MyClass IEnumerator<MyClass>.Current
    {
        get
        {
            if (index == -1)
                return null;
            else
                return collection[index];
        }
    }
    void IDisposable.Dispose()
    {
        collection = null;
    }
    object IEnumerator.Current
    {
        get
        {
            if (index == -1)
                return null;
            else
                return collection[index];
        }
    }
    bool IEnumerator.MoveNext()
    {
        index++;
        return index >= collection.Count;
    }
    void IEnumerator.Reset()
    {
        index = -1;
    }
    IEnumerator<MyClass> IEnumerable<MyClass>.GetEnumerator()
    {
        return (collection as IEnumerable<MyClass>).GetEnumerator();
    }
    IEnumerator IEnumerable.GetEnumerator()
    {
        return (collection as IEnumerable).GetEnumerator();
    }
}