'Determine which renderer and media type to use render the response.'

def perform_content_negotiation(self, request, force=False):

    renderers = self.get_renderers()
    conneg = self.get_content_negotiator()
    try:
        return conneg.select_renderer(request, renderers, self.format_kwarg)
    except Exception:
        if force:
            return (renderers[0], renderers[0].media_type)
        raise
