Constant ITEM_ENERGY 

pub const ITEM_ENERGY: ItemCapabilityKey<dyn EnergyHandler>;

Energy held by an item, as NeoForge 26.3’s Capabilities.Energy.ITEM: a handler for the item at one place, found with ItemPlace::capability, whose changes rewrite the item there with an exchange of one, so from a stack of more than one the changed item splits off. Vanilla has no energy items, so only mods answer it.