code: public String writeEntry(Object entity, String contextUrl) throws ODataRenderException {
  
          this.contextURL = checkNotNull(contextUrl);
  
          try {
              return writeJson(entity, null);
          } catch (IOException | IllegalAccessException | NoSuchFieldException |
                  ODataEdmException | ODataRenderException e) {
              LOG.error("Not possible to marshall single entity stream JSON");
              throw new ODataRenderException("Not possible to marshall single entity stream JSON: ", e);
          }
      }
docs: Write a single entity (entry) to the JSON stream.
  
  @param entity     The entity to fill in the JSON stream. It can not be {@code null}.
  @param contextUrl The 'Context URL' to write. It can not be {@code null}.
  @return the rendered entry
  @throws ODataRenderException In case it is not possible to write to the JSON stream.