/** * @param string $slug * @return null */ public function setSlug($slug) { if (!isset($this->loadedFields['slug'])) { $this->loadProperties(); } $oldValue = null; if (array_key_exists('slug', $this->loadedValues)) { $oldValue = $this->loadedValues['slug']; } if ($oldValue === $slug) { $this->slug = $slug; return; } return parent::setSlug($slug); }