This .NET class wraps the AcBrTraverser ObjectARX class. 

The EnumeratorBase class is the interface base class for topology traversers. This class defines the functions that are common to all topology traversers, and cannot be instantiated as it has no meaning on its own. It is derived from RXObject in order to provide full-service, runtime type checking for all derived traverser classes.

Autodesk.AutoCAD.BoundaryRepresentation.EnumeratorBase
    Autodesk.AutoCAD.BoundaryRepresentation.BrepComplexEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.BrepEdgeEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.BrepFaceEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.BrepShellEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.BrepVertexEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.ComplexShellEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.EdgeLoopEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.Element2dNodeEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.FaceLoopEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.LoopEdgeEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.LoopVertexEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.Mesh2dElement2dEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.ShellFaceEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.VertexEdgeEnumerator
    Autodesk.AutoCAD.BoundaryRepresentation.VertexLoopEnumerator

Public abstract Class EnumeratorBase
Inherits RXObject
Inherits IEnumerator

public abstract class EnumeratorBase : RXObject, IEnumerator;

The intended use of the EnumeratorBase class is to cast aggregate collections of derived class objects for purposes of storing and retrieving from an array.