@Override
 public int fill(ForgeDirection from, FluidStack resource, boolean doFill) {
   if (hasValidMaster() && resource != null && canFill(from, resource.getFluid())) {
     SmelteryLogic smeltery =
         (SmelteryLogic)
             worldObj.getTileEntity(
                 getMasterPosition().x, getMasterPosition().y, getMasterPosition().z);
     return smeltery.fill(resource, doFill);
   } else {
     return 0;
   }
 }