private void applyUserAgent(PutMediaRequest request, Request<PutMediaRequest> marshalled) {
        if (!marshalled.getHeaders().containsKey("User-Agent")) {
            marshalled.addHeader("User-Agent",
                                 RuntimeHttpUtils.getUserAgent(new ClientConfiguration(),
                                                               request.getRequestClientOptions()
                                                                      .getClientMarker(RequestClientOptions.Marker.USER_AGENT)));
        }
    }
Apply the user agent to the marshalled request (if not already present). Appends a custom marker to track usage of the
Netty based client.
aws-java-sdk-kinesisvideo/src/main/java/com/amazonaws/services/kinesisvideo/AmazonKinesisVideoPutMediaClient.java