This .NET class wraps the AcDbObjectContextCollection ObjectARX class. 

An interface to an application-defined collection of ObjectContext objects. 

Applications implement this interface to define custom object contexts for their context-sensitive objects. Applications must instantiate an instance of the collection (typically one instance for each database) and register it with the ObjectContextManager for each Database which needs to support the context type. Each context collection has a state; this is represented by the collection of contexts, the "current" context, and the ability to lock or unlock context instances.

Autodesk.AutoCAD.DatabaseServices.ObjectContextCollection

Public abstract Class ObjectContextCollection
Inherits RXObject
Inherits IEnumerable

public abstract class ObjectContextCollection : RXObject, IEnumerable;