code: private function variantCssClass()
      {
          if ($this->isVariant()) {
              return 'variant';
          }
          if ($this->isVariantBase()) {
              $result = 'varbase';
  
              if (0 !== $this->getVariants(null)->getCount()) {
                  $result .= ' varbase-with-variants';
              }
              return $result;
          }
  
          return '';
      }
docs: Create the CSS class for variant information.
  
  @return string