public static final int OUTPUT_SLOT = 2, FUEL_SLOT = 0, INGREDIENT_SLOT = 1;
private final Slot fuel, ingredient, output;
public FurnaceInventory() {
super(SIZE);
this.fuel = new Slot(this, FUEL_SLOT);
this.ingredient = new Slot(this, INGREDIENT_SLOT);
this.output = new Slot(this, OUTPUT_SLOT);
}