code: public function renderLabel($customFieldOrClass, $slug = null, array $params = array())
      {
          $resolvedParams = array_merge($this->defaultParams, $params);
          
          $customField = ($customFieldOrClass instanceof CustomField) 
              ? $customFieldOrClass : $this->container->get('chill.custom_field.provider')
                  ->getCustomField($customFieldOrClass, $slug);
          
          return $this->container->get('templating')
              ->render($resolvedParams['label_layout'], array('customField' => $customField));
      }
docs: Twig Extension that is used to render the label of a custom field.
  
  @param CustomField|object|string $customFieldOrClass Either a customField OR a customizable_entity OR the FQDN of the entity
  @param string $slug The slug ONLY necessary if the first argument is NOT a CustomField instance
  @param array $params The parameters for rendering. Currently, 'label_layout' allow to choose a different label. Default is 'ChillCustomFieldsBundle:CustomField:render_label.html.twig'
  @return string HTML representation of the custom field label.