15. Design and implement a hierarchy of classes, such that the code fragment in a client class ArrayList piggyBank -new ArrayList piggyBank.add (new Quarter()) piggyBank.add (new Bill (1)); piggyBank.add (new Nickel )) piggyBank.add (new Dime) piggyBank.add (new Quarter () piggyBank.add (new Bill (5)) System.out.println (piggyBank); double amount-0; for (Money item : piggyBank) amountitem.getAmount (); System.out.printf ("The piggy bank holds $.2f ", amount) displays [quarter, $1, nickel, dime, quarter, $5] The piggy bank holds $6.65 Money should be an interface with one method. Each of the classes Quarter, Nickel, and Dime should extend the same superclass Coin and only have a no-args constructor and a toString method_no fields or other methods