code: @Override
      public DigitalObject transform(DigitalObject in, String jsonConfig)
              throws TransformerException {
          if (!valid) {
              error("Instantiation did not complete.");
          }
          log.debug("Received OID '{}'", in.getId());
          return process(in, jsonConfig);
      }
docs: Transform method
  
  @param object DigitalObject to be transformed
  @param jsonConfig String containing configuration for this item
  @return DigitalObject The object after being transformed
  @throws TransformerException