if ($userInstance->ifUsernameExists() === false) {
// Throw an exception here
throw new UsernameMissingException(array($userInstance, $userName), self::EXCEPTION_USERNAME_NOT_FOUND);
if ($userInstance->ifUsernameExists() === false) {
// Throw an exception here
throw new UsernameMissingException(array($userInstance, $userName), self::EXCEPTION_USERNAME_NOT_FOUND);