How to get a container in which the geometry has changed

Sub OnInit()
    For i=0 To this.ChildContainerCount -1
        this.GetChildContainerByIndex(i).Geometry.RegisterTextChangedCallback()
    Next
End Sub

Sub OnGeometryChanged(geom As Geometry)
    For i=0 To this.ChildContainerCount -1
        If this.GetChildContainerByIndex(i).Geometry.VizId == geom.VizId Then
           println this.GetChildContainerByIndex(i).Name
        End If
    Next
End Sub