Issue a request.

def request(self, *args, **kwargs):
        """Issue a request."""
        headers = self.headers.copy()
        if self.cookiestring:
            headers['Cookie'] = self.cookiestring
        headers.update(kwargs.get('headers', {}))
        kwargs['headers'] = headers

        r = request(*args, **kwargs)
        self.cookies.update(r.cookies)

        return r