def put_request_payment(self, bucket, payer):
        """
        Set request payment configuration on bucket to payer.

        @param bucket: The name of the bucket.
        @param payer: The name of the payer.
        @return: A C{Deferred} that will fire with the result of the request.
        """
        data = RequestPayment(payer).to_xml()
        details = self._details(
            method=b"PUT",
            url_context=self._url_context(bucket=bucket, object_name="?requestPayment"),
            body=data,
        )
        d = self._submit(self._query_factory(details))
        return d