Part$1$: Use case diagram An airline wants to manage the flight reservation. Meetings with future users and experts made it possible to identify the following functionalities: $$ The system will be used by an administrator, managers and future customers. $$ The customer must create an account. $$ The customer must be able to o Consult the different flights offered by the company and possibly make reservations o Validate a reservation by first making payment, o Follow the progress of your reservation o Cancel your reservation The manager is an employee of the company, he must be able to: $$ Manage flights $($add a flight, modify it or cancel it$)$ Manage plane and assign them to flights according to availability $$ In the event of cancellation of a flight, the customer must be informed, and the reservation is automatically cancelled. $$ View reservations and validate or cancel them. The system administrator must be able to: $$ Perform all actions assigned to the manager $$ Manage customer accounts $$ Create and manage manager accounts All users must authenticate before each operation.