I was hoping for a solution like this except this does not work
public void addDuplicate()
{
Set itemReg=GameData.getItemRegistry().getKeys();
List<ResourceLocation> itemList=new ArrayList<ResourceLocation>();
itemList.addAll(itemReg);
for ( ResourceLocation itemName : itemList)
{
Item itemm=GameData.getItemRegistry().getObject(itemName);
GameRegistry.addShapelessRecipe(new ItemStack(itemm), mainEA.CopyCore,itemm);
}
}