Auction UC - Cancel Bid

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1. Cancel Bid
1.1 Brief Description
A Buyer may bid on an item (see the Bid On Item use case). A bid may be cancelled by the Buyer or Seller.
The Seller can cancel a bid if:
· The Seller cannot verify Buyer’s identity
· They Buyer contacts the Seller and requests the cancellation of his/her bid
· The Seller decides to cancel the auction (see Cancel Auction use case)
The Buyer can cancel their bids if:
· The Buyer’s bid is the highest bid
Every time the Seller cancels a bid, s/he must provide an explanation that will be kept in the auction history.
The Seller must be signed in before s/he can cancel a bid (see the Sign In use case).