@Override
        public void onError(Throwable error) {
            // Jdisc will automatically generate an error response in this scenario
            log.log(FINE, error, () -> "ContentChannel.onError(): " + error.getMessage());
            errorReported = true;
        }
Close is complete when we have closed the buffer.
vespaclient-container-plugin/src/main/java/com/yahoo/document/restapi/resource/DocumentV1ApiHandler.java