/**
  * @param ChangedUsername $changedUsername
  */
 public function applyChangedUsername(ChangedUsername $changedUsername)
 {
     $this->username = $changedUsername->newUsername();
 }
 /**
  * @param ChangedUsername $event
  */
 public function handleUsernameChange(ChangedUsername $event)
 {
     $this->updateUsername($event->userIdentifier(), $event->newUsername());
 }