private function parseForecastResponseHeaders($headers)
    {
        $responseHeaders = [
            'cache' => [
                'maxAge' => null,
                'expires' => null
            ],
            'responseTime' => null,
            'apiCalls' => null
        ];
        foreach ($headers as $header) {
            switch (true) {
                case (substr($header, 0, 14) === 'Cache-Control:'):
                    $responseHeaders['cache']['maxAge'] = trim(substr($header, strrpos($header, '=') + 1));
                    break;
                case (substr($header, 0, 8) === 'Expires:'):
                    $responseHeaders['cache']['expires'] = trim(substr($header, 8));
                    break;
                case (substr($header, 0, 21) === 'X-Forecast-API-Calls:'):
                    $responseHeaders['apiCalls'] = trim(substr($header, 21));
                    break;
                case (substr($header, 0, 16) === 'X-Response-Time:'):
                    $responseHeaders['responseTime'] = (int)trim(substr($header, 16));
                    break;
                default:
                    break;
            }
        }
        return $responseHeaders;
    }