try_login optional param "extension_args"

Allows adding extension arguments to the OpenID authentication request.

extension_args is an iterable of (namespace, key, value) tuples.

Example:

try_login(openid_url,
          ask_for=['email', 'fullname'],
          extension_args=[('http://specs.openid.net/extensions/ui/1.0', 'mode', 'popup'),
                          ('http://specs.openid.net/extensions/ui/1.0', 'icon', 'true')])

I have a use case in a production app where this is necessary.