public function expectCT(
        $maxAge    = 31536000,
        $enforce   = true,
        $reportUri = null
    ) {
        Types::assert(
            [
                '?int|?string' => [$maxAge],
                '?string' => [$reportUri]
            ],
            [1, 3]
        );

        if (isset($maxAge) or ! isset($this->expectCT['max-age']))
        {
            $this->expectCT['max-age'] = $maxAge;
        }

        if (isset($enforce) or ! isset($this->expectCT['enforce']))
        {
            $this->expectCT['enforce']
                = (isset($enforce) ? ($enforce == true) : null);
        }

        if (isset($reportUri) or ! isset($this->expectCT['report-uri']))
        {
            $this->expectCT['report-uri'] = $reportUri;
        }
    }