/**
* Get hash code
*
* @return string Hash code
*/
public function getHashCode()
{
return md5(parent::getHashCode() . $this->title->getHashCode() . $this->legend->getHashCode() . $this->plotArea->getHashCode() . $this->view3D->getHashCode() . ($this->includeSpreadsheet ? 1 : 0) . __CLASS__);
}