How to manipulate the response object in django-piston?

Question

I have some existing python code that uses django-piston which returns a dictionary as its response. For example:

from piston.handler import BaseHandler

class FooHandler(BaseHandler):
    allowed_methods = ('GET',)

    @classmethod
    def create(self, request):
        return { 'foo': 'bar' }

This code works fine, and is serialized into JSON with the appropriate HTTP header set (I'm assuming this works by some piston magic involving emitters; for bonus points, feel free to clarify how this behavior works as well, as I'm still getting to know django-piston).

I need to be able to modify the response in arbitrary ways, e.g. setting headers, status codes, etc. without using some pre-baked solution designed for a specific purpose. Is there a convenient way to access the response object in the context of this code and manipulate it, or has the response object not yet been created? In order to get access to a response object, will I have to construct it manually (a la vanilla django), serialize the dictionary, and set the appropriate headers by hand, and thus lose out on some of the useful magic of django-piston?