Just a caveat, since your code makes me think you misunderstand just a wee bit. The implementor matters at the time you make the request, not when you create the user agent object. So in your example, if you add the line

at the end there, I think you'll find that it makes an HTTP/1.1 request, not HTTP/1.0 like your code leads me to believe you might be thinking (your code suggests to me that you think you have now an 'HTTP/1.0 user agent' ($ua) and an 'HTTP/1.1 user agent' ($ua2) and you can just alternate UAs to alternate which protocol to use). See the code I suggested above in my update.

At least, this is the behavior I found when I tested with my version, which may be different from yours.

HTH