public function getContentType()
    {
        switch ($this->input->getFormat()) {

            case InputInterface::FORMAT_JSON:
                return ClientInterface::CONTENT_TYPE_JSON;
                break;

            case InputInterface::FORMAT_TEXT:
                return ClientInterface::CONTENT_TYPE_TEXT;
                break;

            default:
                throw new \LogicException('Allowed invalid input format to be set.');
        }
    }