I am looking for where Class 'Charm' is located

Hi,

I changed my mind and I bought Charm Template for mixing the original HelixUltimate with CharmHelixUltimate for getting light/dark mode.

I think I am close to manage my aim.

In /plugins/system/charmhelixultimate/core/charmhelixultimate.php and /templates/charm/index.php

I see Charm:: that calls Class 'Charm'

Where is located 'Charm' class ?

Thank you for your help...