This .NET class wraps the AcDbObjectContextCollectionIterator ObjectARX class. 

An iterator interface for ObjectContext objects stored in an ObjectContextCollection. 

Applications that provide custom ObjectContextCollection implementations must also implement this interface in a custom iterator for their collection.

Autodesk.AutoCAD.DatabaseServices.ObjectContextCollectionEnumerator

Public abstract Class ObjectContextCollectionEnumerator
Inherits RXObject
Inherits IEnumerator

public abstract class ObjectContextCollectionEnumerator : RXObject, IEnumerator;