Best way to implement server-side singleton?

Hi, I’m working on a set of custom data sources and would like to have something that behaves like a SMProxy, but results in only one server-side instance of the VTKObject at runtime. Where would be the best place to do this? In my vtkObject-derived class, or maybe a custom SMProxy?

A vtkObject-derived class would be my vote. vtkPVGeneralSettings may be a good example to look at as an option.