/** * @param string $parent * @return null */ public function setParent($parent = '0') { if (!isset($this->loadedFields['parent'])) { $this->loadProperties(); } $oldValue = null; if (array_key_exists('parent', $this->loadedValues)) { $oldValue = $this->loadedValues['parent']; } if ($oldValue === $parent) { $this->parent = $parent; return; } return parent::setParent($parent); }