public class ExampleItemInterface<T extends SmartAnimalBase> implements TravelersItemInterface<T> {
    private Supplier<Item> spawnEgg;

    private Supplier<Item> rawMeat;
    private Supplier<Item> cookedMeat;

    @Override
    public void init(TravelersAnimalAttributes<T> travelersAnimalAttributes, TravelersAnimal<T> travelersAnimal) {
        var name = travelersAnimalAttributes.getAnimalName();
        rawMeat = ExampleItemRegistry.registerItem(name + "_raw", () -> new Item(new Item.Properties().food(new FoodProperties.Builder().build())));
        cookedMeat = ExampleItemRegistry.registerItem(name + "_cooked", () -> new Item(new Item.Properties().food(new FoodProperties.Builder().build())));
    }

    public Supplier<Item> getRawMeat() {
        return rawMeat;
    }

    public Supplier<Item> getCookedMeat() {
        return cookedMeat;
    }

    @Override
    public void initSpawnEgg(TravelersAnimalAttributes<?> travelersAnimalAttributes, TravelersAnimal<?> travelersAnimal) {
        // This runs later because you NEED the entityType to be initialized first.
        spawnEgg = ExampleItemRegistry.registerItem(travelersAnimalAttributes.getAnimalName() + "_spawn_egg", () ->
        // Cast is needed because the entityType's class is unknown
        new DeferredSpawnEggItem(() -> (EntityType<? extends Mob>)
            travelersAnimal.getEntityType().get(), 0, 0, new Item.Properties()));
    }

    public Supplier<Item> getSpawnEgg() {
        return spawnEgg;
    }

    @Override
    public HashMap<ItemLike, DropObject> initDrops(TravelersItemInterface<T> travelersItemInterface, HashMap<ItemLike, DropObject> hashMap) {
        // Unused in this example
        return null;
    }

    @Override
    public @Nullable ItemStack getPickItem(SmartAnimalBase smartAnimalBase) {
        // The item the entity gets if you middle-click it.
        return spawnEgg.get().getDefaultInstance();
    }
}