src/Neutrino/Cli/Question/ConfirmationQuestion.php
public function normalize($response)
    {
        if (is_bool($response)) {
            return $response;
        }

        $response = parent::normalize($response);

        if ($response === null || $response === '') {
            return $this->default;
        }

        return (bool)preg_match($this->answerRegex, $response);
    }
public function normalize($response)
    {
        if (is_bool($response)) {
            return $response;
        }

        $response = parent::normalize($response);

        if ($response === null || $response === '') {
            return $this->default;
        }

        return (bool)preg_match($this->answerRegex, $response);
    }
@param $response

@return bool|null|string