code: public function createVariant(ConfigInterface $objConfig)
      {
          $objItem = $this->getMetaModel()->findById($objConfig->getId())->varCopy();
  
          if (!$objItem) {
              return null;
          }
  
          $model = new Model($objItem);
          $model->setMeta($model::IS_CHANGED, true);
  
          return $model;
      }
docs: Fetch a variant of a single record by id.
  
  @param ConfigInterface $objConfig The config holding the id of the base model.
  
  @return null|ModelInterface