多选题 Given:
2. public class Contact {
3. private String name;
4. private String city;
5. String getName() {return name; }
6. void setName(String n) {name = n; }
7. void setCity(String c) {
8. if(c == null) throw new NullPointerException();
9. city = c;
10. }
11. String getCity() {return city; }
12. }
Which are true? (Choose all that apply.)