public function display()
    {
        $this->output = $this->content;

        //if content is an exception then
        //handle
        if ($this->content instanceof Exception) {
            $data = array();
            $data['code'] = $this->content->getCode();
            $data['message'] = (string) $this->content->getMessage();
            if ($this->content instanceof AnErrorException) {
                $data['errors'] = $this->_toData($this->content->getErrors());
            }
           //Encode data
            $this->output = json_encode($data);
        }

        return $this->output;
    }