EXERCISE 4.28
Add a close method to the Auction class. This should iterate over the collection of lots and print out details of all the lots. You can use either a for-each loop or a while loop. Any lot that has had at least one bid for it is considered to be sold. For lots that have been sold, the details should include the name of the successful bidder, and the value of the winning bid. For lots that have not been sold, print a message that indicates this fact.