'Begin a response with the given status and other headers.'

def respond(self, status=HTTP_OK, content_type=None, headers=None):

    if headers:
        self._headers.extend(headers)
    if content_type:
        self._headers.append(('Content-Type', content_type))
    self._headers.extend(self._cache_headers)
    return self._start_response(status, self._headers)
