public function display($message = null)
    {
        // if passed message is null get exception msg
        if (!$message) {
            $message = $this->message;
        }
        
        // hide root path from exception
        $message = Str::replace(root, '$DOCUMENT_ROOT', $message);
        $message = strip_tags($message);

        // generate response based on environment type
        switch (env_type) {
            case 'html':
                return $this->sendHTML($message);
            case 'json':
                return $this->sendJSON($message);
        }
        
        return $message;
    }