@classmethod
def remove_access(cls, ns, entity, provider):
    """
        Removes the access for the given entity to the provider in the
        access namespace.
        :param string ns: The namespace of the access domain.
        :param Entity entity: An entity.
        :param mongoengine.Document provider: The provider of the access.
        """
    cls.objects(ns=ns, entity=entity, provider=provider).delete(safe=True)
