In the Viewport VR Preview, an unusual and complicated import
manipulates sys.path to import a class from a file that is already
importable anyway.
There is no documented reason for this, and the common way to subclass an RNA type in python is by using its `bpy.types....` registered class, _not_ by directly subclassing the python type used to declare/register the parent type.
Pull Request: https://projects.blender.org/blender/blender/pulls/147656
0c22ef5ae7