What is
The main MODEL (hierarchy of different Ticket types) is in "ticket" package. So a separate class diagram of this MODEL would be useful. In addition to the core MODEL there are supporting service layer interfaces in the "ticket" package e.g. TicketManager (the main facade into the ticket MODEL), TicketRegistry (internal ticket cache), TicketFactory (internal factory for vending tickets), TicketCreator (TicketFactory's helper interface for instantiating a particular type of a Ticket), ExpirationPolicy (Ticket's strategy collaborator to define different expiration policies for tickets), etc., etc.
Ideas
It's turtles all the way down.