'Creates a Policy.
For a full list of available parameters, please refer to the official
API reference:
http://developer.openstack.org/api-ref/identity/v3/index.html#create-policy'

def create_policy(self, **kwargs):

    post_body = json.dumps({'policy': kwargs})
    (resp, body) = self.post('policies', post_body)
    self.expected_success(201, resp.status)
    body = json.loads(body)
    return rest_client.ResponseBody(resp, body)
