'List access tokens.
For more information, please refer to the official API reference:
http://developer.openstack.org/api-ref/identity/v3-ext/#list-access-tokens'

def list_access_tokens(self, user_id):

    (resp, body) = self.get(('users/%s/OS-OAUTH1/access_tokens' % user_id))
    self.expected_success(200, resp.status)
    body = json.loads(body)
    return rest_client.ResponseBody(resp, body)
