public class CelestialPowerPedestalTileEntity extends TileEntity {

    public static final  int                        slots                  = 1;
    public               ItemStackHandler           inv                    = new ItemStackHandler();
    private final        LazyOptional<IItemHandler> capabilityLazyOptional = LazyOptional.of(() -> inv);

    public CelestialPowerPedestalTileEntity() {
        super(ModTileEntities.CELESTIAL_POWER_PEDESTAL_TILE_ENTITY.get());
    }

    public boolean isFillable() {
        return inv.getStackInSlot(0).getItem() != ModItems.CELESTIAL_POWER_EYE.get();
    }

    @Override
    public void read(BlockState state, CompoundNBT nbt) {
        super.read(state, nbt);
        inv.deserializeNBT(nbt.getCompound("Inv"));
    }

    @Nonnull
    @Override
    public <T> LazyOptional<T> getCapability(Capability<T> cap, Direction side) {
        if (cap == CapabilityItemHandler.ITEM_HANDLER_CAPABILITY) {
            return capabilityLazyOptional.cast();
        }
        return super.getCapability(cap, side);
    }

    @Override
    protected void invalidateCaps() {
        super.invalidateCaps();
        capabilityLazyOptional.invalidate();
    }

    @Nullable
    @Override
    public SUpdateTileEntityPacket getUpdatePacket() {
        return new SUpdateTileEntityPacket(this.pos, -1, getUpdateTag());
    }

    @Override
    public void onDataPacket(NetworkManager net, SUpdateTileEntityPacket pkt) {
        handleUpdateTag(this.getBlockState(), pkt.getNbtCompound());
    }

    @Override
    public CompoundNBT getUpdateTag() {
        CompoundNBT nbt = super.getUpdateTag();
        nbt.put("Inv", inv.serializeNBT());
        return nbt;
    }

    @Override
    public void handleUpdateTag(BlockState state, CompoundNBT tag) {
        this.read(state, tag);
    }
}