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