/**
 * Card represents an UW ID card.  
 * Cards are immutable.
 *
 * The abstract state of a card is {name, id, background, type, privileges}
 * where
 * @specfield name: string // name of person who holds this card
 * @specfield id: string  // 7-digit id of person who holds this card
 * @specfield background: color // background color of the card
 * @specfield type: string // the type of person holding the card
 * @specfield privileges: set // the access privileges of this card
 *
 * An example card is {"Fake Name", 01234567, purple, "student",
 * {cse}}
 **/
public class Card {
 
    /** @effects constructs a new Card c, such that
     *    c.name = name &&
     *    c.id = idNumber &&
     *    c.background = background &&
     *    c.type = type &&
     *    c.privileges contains the elements of privileges
     **/
    public Card(String name,
		String idNumber,
		Color background,
		String type,
		List privileges) {

      // implementation omitted.

    }
}