Given the project AuctionSystem¹ auction system as described in the book on p. 170.

Methods

• Add a method close() to the Auction class. This should iterate over the collection of items iterating (using a for-each loop) and printing print details of all items. Every item on which at least one bid is considered sold, so look for Lot objects for which the highest bid field is not None. For lots with a bidder, the following should be printed in the console:

  Lot number: [lot number] - Winner: [name] - Highest Bid: [highest_bid]

  For items without a bidder, print the following:

  Lot number: [lot number] - No bid

• Add a method get_unsold with the following header def get_unsold(). This method should search the lots field and store the lots that are not sold in a new local list variable. What you are looking for are lot objects for which the field highest_bid is None. At the end of the method, return the list of unsold lots. If all lots are sold, the method returns None.
• Rewrite the get_lot method so that it does not depend on the index number in the list lots, but looks up a Lot by looking at the lot number.
• Add a method remove() to the Auction class with the following header def remove(number:int). The method removes the lot with the given lot number and returns the lot that was removed. The method returns None if no lot was removed because it does not exist.