private function isSingularResponse($answer)
    {
        return (
            is_string($answer) ||
            is_callable($answer) ||
            array_key_exists('buttons', $answer) ||
            array_key_exists('elements', $answer) || // For Generic or Receipt
            (is_array($answer) && isset($answer[0]) && is_array($answer[0]) && array_key_exists(
                'title',
                    $answer[0]
            )) || // For Generic
            isset($answer['text']) || // For Button
            isset($answer['type']) || // For type => content =>
            isset($answer['attachment']) // For attachment
        );
    }