[Twisted-web] What's the correct way to deal with render_GET and unicode?

If I return a unicode string from my Resource's render_GET, I get a 500 error that says "Request did not return a string". I guess that means I'm responsible for encoding the response, but do I then need to write a render_HEAD to set the charset for the message? Are there any examples of how to do this? --- Mark Wright markscottwright@gmail.com