/** Writes a tile entity to NBT. */
 @Override
 public void writeToNBT(NBTTagCompound NBT) {
   super.writeToNBT(NBT);
   NBT.setInteger("liquidLevel", liquidLevel);
   NBT.setInteger("liquid", liquidID);
 }
 /** Reads a tile entity from NBT. */
 @Override
 public void readFromNBT(NBTTagCompound NBT) {
   super.readFromNBT(NBT);
   liquidLevel = NBT.getInteger("liquidLevel");
   liquidID = NBT.getInteger("liquid");
 }