public function getBotParam(string $param, $default = null)
    {
        $param_path = explode('.', $param);

        $value = $this->bot_params[array_shift($param_path)] ?? null;
        foreach ($param_path as $sub_param_key) {
            $value = $value[$sub_param_key] ?? null;
            if (null === $value) {
                break;
            }
        }

        return $value ?? $default;
    }