code: Oid executeOperation(Entity subject, String operationName)
              throws UnsupportedOperationException {
          Asset asset = getAsset(subject);
  
          return executeOperation(asset, operationName);
      }
docs: Be sure to call Entity.Save() before or after calling this depending on
  the operation result.
  
  @param subject       asset will be found for.
  @param operationName operator name.
  @return object identifier.
  @throws UnsupportedOperationException in case invalid state for the
  Operation.