Exercise $4\mathrm{.}48$ Add a close method to the Auction class. This should iterate over the collection of lots and print out details of all the lots. Use a for$-$each loop. Any lot that has had at least one bid for it is considered to be sold, so what you are looking for is Lot objects whose highestBid field is not nu$11.$ Use a local variable inside the loop to store the value returned from calls to the getHighestBid method, and then test that variable for the null value.

For lots with a bidder, the details should include the name of the successful bidder and the value of the winning bid. For lots with no bidder, print a message that indicates this.