public function attachPdf($filepath)
    {
        $content = file_get_contents($filepath);
        $filename = basename($filepath);

        return $this->performEvent('attach', array('filename' => $filename, 'content' => base64_encode($content)));
    }
public function attachPdf($filepath)
    {
        $content = file_get_contents($filepath);
        $filename = basename($filepath);

        return $this->performEvent('attach', array('filename' => $filename, 'content' => base64_encode($content)));
    }
public function attachPdf ( $ filepath ) { $ content = file_get_contents ( $ filepath ) ; $ filename = basename ( $ filepath ) ; return $ this -> performEvent ( 'attach' , array ( 'filename' => $ filename , 'content' => base64_encode ( $ content ) ) ) ; }
Attach a PDF to the billogram.

@param $filepath
@return $this
Attach a PDF to the billogram .