How to override "core_api_version"?

[truebit]

I'd like to use other core api version like 2.0,
I tried below code, but without luck:

from stashy.client import StashClient
import stashy
StashClient.core_api_version = '2.0'
s= stashy.connect('http://git.example.com', 'admin', 'foobar')
s.admin.groups.url()

s.admin.groups.url() still returns 1.0

[truebit]

I found the core_api_path is still api/1.0. So workaround is to override core_api_path instead of core_api_version