'Delete permissions for an ACL entity on a container or object.
:param container_name: The container name.
:type container_name: ``str``
:param object_name: The object name. Optional. Not providing an object
will delete a container permission.
:type object_name: ``str``
:param entity: The entity to whose permission will be deleted.
Optional. If not provided, the role will be applied to the
authenticated user, if using an OAuth2 authentication scheme.
:type entity: ``str`` or ``None``'

def ex_delete_permissions(self, container_name, object_name=None, entity=None):

    object_name = _clean_object_name(object_name)
    if (not entity):
        user_id = self._get_user()
        if (not user_id):
            raise ValueError('Must    provide    an    entity.    Driver    is    not    using    an    authenticated    user.')
        else:
            entity = ('user-%s' % user_id)
    if object_name:
        url = ('/storage/v1/b/%s/o/%s/acl/%s' % (container_name, object_name, entity))
    else:
        url = ('/storage/v1/b/%s/acl/%s' % (container_name, entity))
    self.json_connection.request(url, method='DELETE')
