'Use the authentication plugin to authenticate and set the auth token.
:param force_reauth: For re-authentication to bypass cache.'

def _authenticate(self, force_reauth=False):

    auth_plugin = self.auth_plugin
    if ((not auth_plugin.is_authenticated) or force_reauth):
        auth_plugin.authenticate()
    self.auth_token = auth_plugin.auth_token
    management_url = auth_plugin.management_url
    if (management_url and self.configure_via_auth):
        self.configure_from_url(management_url)
