/** Marshall the given parameter object, and output to a JSONWriter */
  public void marshall(Artifact artifact, JSONWriter jsonWriter) {
    if (artifact == null) {
      throw new AmazonClientException("Invalid argument passed to marshall(...)");
    }

    try {
      jsonWriter.object();

      if (artifact.getName() != null) {
        jsonWriter.key("name").value(artifact.getName());
      }

      if (artifact.getRevision() != null) {
        jsonWriter.key("revision").value(artifact.getRevision());
      }

      if (artifact.getLocation() != null) {
        jsonWriter.key("location");
        ArtifactLocationJsonMarshaller.getInstance().marshall(artifact.getLocation(), jsonWriter);
      }

      jsonWriter.endObject();
    } catch (Throwable t) {
      throw new AmazonClientException("Unable to marshall request to JSON: " + t.getMessage(), t);
    }
  }