FirstName constructor

FirstName(String? str)

Returns a valid FirstName object.

Throws ValueException:

• RequiredValueException if str is null or empty.
• InvalidValueException if str is not a valid first name.

Implementation

factory FirstName(String? str) {
  if (str == null || str.isEmpty) {
    throw const RequiredValueException();
  } else if (!validate(str)) {
    throw InvalidValueException(str);
  }
  return FirstName._(str);
}