LastName constructor
Creates an extended version of Name and flags it as a last name type.
Some people may keep their mother
's surname and want to keep a clear cut
from their father
's surname. However, there are no clear rules about it.
Implementation
LastName(String father, [String? mother, this.format = Surname.father])
: super(father, Namon.lastName) {
if (mother != null) {
_validate(mother);
_mother = Name.last(mother);
}
}