code: private function addCustomElements(array $elements, HTMLPurifier_HTMLDefinition $definition)
      {
          foreach ($elements as $element) {
              // Get configuration of element
              $name = $element[0];
              $contentSet = $element[1];
              $allowedChildren = $element[2];
              $attributeCollection = $element[3];
              $attributes = isset($element[4]) ? $element[4] : null;
  
              if (!empty($attributes)) {
                  $definition->addElement($name, $contentSet, $allowedChildren, $attributeCollection, $attributes);
              } else {
                  $definition->addElement($name, $contentSet, $allowedChildren, $attributeCollection);
              }
          }
      }
docs: Add provided elements to the provided definition
  
  @param array $elements
  @param HTMLPurifier_HTMLDefinition $definition
  
  @return HTMLPurifier_HTMLDefinition $definition