code: public void marshalEntry(Object content, OutputStream stream)
              throws JAXBException {
          marshaller.marshal(createEntry(content), stream);
      }
docs: Convert the given content into an ATOM entry and write it to the given
  stream.
  
  @param content
  Content object to send
  @param stream
  Stream to write to
  @throws JAXBException
  if content is malformed/not marshallable