Ernestine is writing code for a local hardware store; they want to be able to keep better records on their inventory. She has written a class InventoryItems. She is now in the process of writing subclasses of InventoryItems for each of the categories of the stores inventory. She has started the subclass that will handle the stores electrical supply items. So far she has started the first line of the subclass definition: public class Electrical What else does she need to write on this line? What is the purpose of this additional code in the statement?