Is it possible to assemble the HTML responses out of order?  ie I want to
included a javascript file (which I believe needs to be stated in the
Headers).  I don't know I need to include this until I have already begun
processing the body (ie to support a certain field in the form).  I note
there is a set_headers method but can't figure it out (I set it in the
request.response but they don't seem to render).  Ideally I would like to
add to the headers to response instance after already appending to the body
of the response and then have the entire response rendered at the very end.
Is this supported?  Is this smart?

-Brian