If a group of passengers travel together, the following changes must be made.

• Add a new class PassengerGroup with the responsibility of reporting a list of the passengers in the group.
• Class Passenger: Add the responsibility to report the group the passenger is in (if any).
• Class Itinerary: Add the responsibility to add a reservation with a flight and one or more seats; Collaborators: None
• Flight: no changes
• Seat: no changes
• The person using the flight reservation system will be responsible for making reservations on a particular flight for all the passengers in the group. If the plane fills up before all of the reservations are make, the person will be responsible for deleting the reservations that have already been made for group members on that plane.