This erro no make sense

public class Contact{
  private int id;
  private String firstName;
  private String lastName;
  private String email;

  public Contact(int id, String firstName, String lastName, String email){
    this.id = id;
    this.firstName = firstName;
    this.lastName = lastName;
    this.email = email;
  }

  public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }

        public String getFirstName() {
            return firstName;
        }

        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }

        public String getLastName() {
            return lastName;
        }

        public void setLastName(String lastName) {
            this.lastName = lastName;
        }

        public String getEmail() {
            return email;
        }

        public void setEmail(String email) {
            this.email = email;
        }

}