public Person(LinkedList<String> firstName, String lastName, Date birthday,
LinkedList<TelephoneNumber> mobilNumber, LinkedList<Email> email,
Group group, LinkedList<PositionInformation> positionInformation) throws EmptyNameException{
if (firstName == null || lastName == null || firstName.isEmpty() ||
firstName.getFirst().equals("") || lastName.equals("")){
throw new EmptyNameException(); //<== EXIT
}
this.firstName = firstName;
this.lastName = lastName;
if (birthday != null){
this.birthday = birthday;