addValidItem(BlockRailcraftSlab.getItem(EnumBlockMaterial.ICE));
addValidItem(Items.snowball);
}
public void compactInventory(ItemStack backpack) {
StandaloneInventory inv = new StandaloneInventory(45);
NBTTagCompound data = backpack.getTagCompound();
if (data == null) return;
InvTools.readInvFromNBT(inv, INV_TAG, data);
int numSnowballs = InvTools.countItems(inv, SNOWBALL);
if (numSnowballs >= 16) {