>>> from keystoneclient.auth.identity import v3
>>> from keystoneclient import session
>>> from keystoneclient.v3 import client
>>> from constants import constants as con
>>> auth = v3.Password(
...             auth_url=con.auth_url,
...             username=con.username,
...             password=con.password,
...             project_name=con.project_name,
...             project_domain_name=con.project_domain_name,
...             user_domain_name=con.user_domain_name)
>>>
>>> session = session.Session(auth=auth)
>>> key_cli = client.Client(session=session)
>>>
>>> from novaclient import client
>>> from novaclient import api_versions
>>> nova = client.Client("2.1", session=session)
>>> latest_version = api_versions.discover_version(nova, "2.latest")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/novaclient/api_versions.py", line 269, in discover_version
    if (not requested_version.is_latest() and
AttributeError: 'str' object has no attribute 'is_latest'