How to know if an object was selected using Sub-Object selecting?

This script seems to work once you cancel out the filter:

import Rhino
import scriptcontext

def test_get_brep_face():
    go = Rhino.Input.Custom.GetObject()
    go.SetCommandPrompt("Select surfaces")
    #go.GeometryFilter = Rhino.DocObjects.ObjectType.Surface
    go.SubObjectSelect = True
    go.GetMultiple(1, 0)
    if go.CommandResult()!= Rhino.Commands.Result.Success:
        return
        
    for objref in go.Objects():
        print(objref.ObjectId)
        print(objref.GeometryComponentIndex.ComponentIndexType)
        print(objref.GeometryComponentIndex.Index)

if __name__ == "__main__":
    test_get_brep_face()