onExpChange
public void onExpChange(org.bukkit.event.player.PlayerExpChangeEvent event)
This manages the Mending Enchantment for Custom Items. Surprisingly, this
does work perfectly as vanilla might pick the item with Mending and
Unbreakable but not apply the durability change as it is unbreakable and
instead give the levels to the player, which we can use here! :D This is
why I'm only using Unbreakable items and not all items with Mending and
Fake Durability and it's also why this is hard coded, and there's no way
to change the modifier.