convert
Converts getClassById raw slot ID into its local slot ID into whichever of the two inventories the slot points to.
If the raw slot refers to the upper inventory, it will be returned unchanged and thus be suitable for getTopInventory().getItem(); if it refers to the lower inventory, the output will differ from the input and be suitable for getBottomInventory().getItem().
Return
The converted slot ID.
Parameters
raw
The raw slot ID.