public function getHTTPPrefer()
    {
        $result = [
            // can be true or false
            'respond-async' => false,
            // Could be set to 'representation' or 'minimal'.
            'return' => null,
            // Used as a timeout, is usually a number.
            'wait' => null,
            // can be 'strict' or 'lenient'.
            'handling' => false,
        ];

        if ($prefer = $this->httpRequest->getHeader('Prefer')) {
            $result = array_merge(
                $result,
                HTTP\parsePrefer($prefer)
            );
        } elseif ('t' == $this->httpRequest->getHeader('Brief')) {
            $result['return'] = 'minimal';
        }

        return $result;
    }