"name" and "value" are required for setHeader().

[bampisSyk]

I'm getting the above message when i'm trying to run the example you've posted for getting all countries

[willfrew]

Have you logged in with session.login()? I was getting this error in some test cases but realised it was because I hadn't logged in.

The library is attempting to set the session key header but since I hadn't logged in, the session key was undefined.