def METHOD_NAME(self, email: str, **kwargs) -> Tuple[bool, 'User']:
    """Get the existing user with a given email address or create an unstored one
    :param kwargs: The properties of the user to get or create
    :return: The corresponding user object
    :raises: :class:`aiida.common.exceptions.MultipleObjectsError`,
        :class:`aiida.common.exceptions.NotExistent`
    """
    try:
        return False, self.get(email=email)
    except exceptions.NotExistent:
        return True, User(backend=self.backend, email=email, **kwargs)