ItemStacks are automatically converted using a [converter](https://github.com/MightyPirates/OpenComputers/blob/master/src/main/java/li/cil/oc/api/driver/Converter.java) that's [built into OC](https://github.com/MightyPirates/OpenComputers/blob/master/src/main/scala/li/cil/oc/server/driver/converter/ItemStack.scala), so this shouldn't be necessary?