@Override
                protected void onDisable() { }
This test specifically validates the corrected PBR rendering when combined
with instancing, as addressed in issue #2435.

<p>
It creates an InstancedNode with a PBR-materialized Box to ensure the fix in 
PBRLighting.vert correctly handles world position calculations for instanced geometry.
</p>

@author Ryan McDonough - original test
@author Richard Tingle (aka richtea) - screenshot test adaptation
jme3-screenshot-tests/src/test/java/org/jmonkeyengine/screenshottests/scene/instancing/TestInstanceNodeWithPbr.java