/**
  * Unloads whole document from memory.
  * CAUTION! None further operations will be possible on this document.
  * All objects refering to it will be useless.
  *
  * @return PhpQueryObject|QueryTemplatesSource|QueryTemplatesParse|QueryTemplatesSourceQuery
  */
 public function unloadDocument()
 {
     phpQuery::unloadDocuments($this->getDocumentID());
 }