Initialise a Tornado AsyncClient and send the request to the sentry
        server. If the callback is a callable, it will be called with the
        response.

def _send_remote(self, url, data, headers=None, callback=None):
        """
        Initialise a Tornado AsyncClient and send the request to the sentry
        server. If the callback is a callable, it will be called with the
        response.
        """
        if headers is None:
            headers = {}

        return AsyncHTTPClient().fetch(
            url, callback, method="POST", body=data, headers=headers,
            validate_cert=self.validate_cert
        )