Person Rich Object Domain

PersonRichObject.cs

class Person {
  
  public string FirstName { get; private set; }
  public string LastName { get; private set; }
  
  public Person(string firstName, string lastName) {
    ChangeName(firstName, lastName);
  }
  
  public void ChangeName(string firstName, string lastName) {
    if (firstName == null) throw new ArgumentException("firstName cannot be null");
    if (lastName == null) throw new ArgumentException("lastName cannot be null");

    FirstName = firstName;
    LastName = lastName;
  }
}