sb-auction

Big lines

Auction has three states: PLANNED, OPEN, ENDED, CLOSED
User can register to a PLANNED Auction.
Auction notifies the registered Users that it has started (Auction.state is OPEN)
User can bid and see bids as long as the Action is OPEN.
Once an Auction is CLOSE every registered User gets notified and the winner is known. With this, I think we can illustrate event based design, highly concurrent processing, smooth exception handling (
- ex1.: because of high concurrency, what if a bid received at T1 is less than another received at T0
- ex2: what if a bid is received right after the Auction has been closed )