/** * Stores a copy of the current TCPDF object used for undo operation. * @public * @since 4.5.029 (2009-03-19) */ public function startTransaction() { if (isset($this->objcopy)) { // remove previous copy $this->commitTransaction(); } // record current page number and Y position $this->start_transaction_page = $this->page; $this->start_transaction_y = $this->y; // clone current object $this->objcopy = TCPDF_STATIC::objclone($this); }