function stream($filename, $options = null)
 {
     // Store the last page in the page cache
     if (!is_null($this->_current_page_id)) {
         $this->_pdf->close_object();
         $this->_pdf->add_object($this->_current_page_id, "add");
         Page_Cache::store_page($this->_cache_id, $this->_pdf->get_page_number(), $this->_pdf->serialize_object($this->_current_page_id));
         Page_Cache::store_fonts($this->_cache_id, $this->_fonts);
         $this->_current_page_id = null;
     }
     $this->_pdf->stream($filename);
 }