def METHOD_NAME(self, user):
    if not self.registration_required:
        raise RegistrationNotRequiredException(event=self, user=user)
    elif not self.registration_open():
        raise RegistrationNotOpen(event=self, user=user)
    elif not self.allowed_to_attend(user):
        raise RegistrationNotAllowed(
            "Arrangementet er ikke åpent for ditt kull.", event=self, user=user
        )
    elif not self.user_penalty_limit(user):
        raise RegistrationNotAllowed(
            "Du har for mange prikker!", event=self, user=user
        )