fkooman\OAuth\Client\RefreshToken::__construct PHP Method

    public function __construct(array $data)
    {
        parent::__construct($data);
        foreach (array('refresh_token') as $key) {
            if (!array_key_exists($key, $data)) {
                throw new TokenException(sprintf("missing field '%s'", $key));
            }
        }
        $this->setRefreshToken($data['refresh_token']);
    }