This collection class is used to specify the list of checked indexes in the CheckedListBox control.

public class CheckedListBox.CheckedIndexCollection : IList, ICollection, IEnumerable {
// Public Instance Properties
   public int Count{get; }
// implements ICollection
   public bool IsReadOnly{get; }
// implements IList
   public int this{get; }
// Public Instance Methods
   public bool Contains(int index);
   public void CopyTo(Array dest, int index);  // implements ICollection
   public IEnumerator GetEnumerator();  // implements IEnumerable
   public int IndexOf(int index);
}