public void loadInventroy(String world) {
   try {
     File f = new File(world, "store.dat");
     DataInputStream input = new DataInputStream(new FileInputStream(f));
     SKTagCompound comp = new SKTagCompound();
     comp.readTagContents(input);
     credits = comp.getInteger("credits");
     readFromNBT(comp);
     input.close();
   } catch (FileNotFoundException e) {
     System.out.println("No store exists for " + world);
     credits = 0;
   } catch (IOException e) {
     e.printStackTrace();
   }
   previousValue = calcValue();
 }
  public void saveInventory(String world) {

    try {
      File f = new File(world, "store.dat");
      f.createNewFile();
      DataOutputStream out = new DataOutputStream(new FileOutputStream(f));
      SKTagCompound comp = new SKTagCompound();
      comp.setInteger("credits", credits);
      writeToNBT(comp);
      comp.writeTagContents(out);
      out.close();
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }