A Train ticket selling machine works as follows: A customer who wants to buy a ticket for a particular journey enters the destination, the station to start from, the date and time of departure, the class in which he wants to travel. The information system which returns data about one or more possible trips matching the query. Each trip is described by its number, date of departure, exact time of departure, time of arrival, and price. The customer chooses one of the possible trips found by the system and reserves a seat or more in this trip by getting a ticket for it. The ticket contains some further information such as the date of issue. Before the customer receives one or more tickets, he has to pay for them. The system supports two different methods of payment – pay by credit card or by inserting bank notes. If you pay by credit card, the system registers the number of the credit card and its expiration date. Independent of the payment method the customer chooses, the system always records the amount of money being paid, the date of the payment and the signature of the customer. Draw a class diagram for this system.