/** * Get a handle for this object * * This function returns an unique identifier for the object. This id can be used as a hash key for storing objects * or for identifying an object * * @return string A string that is unique */ public function getHandle() { if (isset($this->_identity_key)) { $handle = $this->getProperty($this->_identity_key); } else { $handle = parent::getHandle(); } return $handle; }