The interior of a multipoint is the set of points in the collection, the boundary is the empty set, and the exterior is the set of points that are not in the collection.
A Multipoint is based upon the parent Geometry class. The Geometry class is immutable which means that you can not change its shape once it is created. If you need to modify a Multipoint once it has been created, use the MultipointBuilder class instead. The MultipointBuilder.ToGeometry method will provide you with the Multipoint object.
System.Object
ArcGIS.Core.Geometry.Geometry
ArcGIS.Core.Geometry.Multipoint
Target Platforms: Windows 10, Windows 8.1