Gets an entity object from the ACL.

        :type entity: :class:`_ACLEntity` or string
        :param entity: The entity to get lookup in the ACL.

        :type default: anything
        :param default: This value will be returned if the entity
                        doesn't exist.

        :rtype: :class:`_ACLEntity`
        :returns: The corresponding entity or the value provided
                  to ``default``.

def get_entity(self, entity, default=None):
        """Gets an entity object from the ACL.

        :type entity: :class:`_ACLEntity` or string
        :param entity: The entity to get lookup in the ACL.

        :type default: anything
        :param default: This value will be returned if the entity
                        doesn't exist.

        :rtype: :class:`_ACLEntity`
        :returns: The corresponding entity or the value provided
                  to ``default``.
        """
        self._ensure_loaded()
        return self.entities.get(str(entity), default)