function __construct(int $statusCode = 200, array $headers = [], $body = NULL)
{
foreach ($headers as $name => $header) {
$this->headerNames[strtoupper($name)] = $name;
}
parent::__construct($statusCode, $headers, $body);
$this->headerNames += ['CACHE-CONTROL' => 'Cache-Control', 'CONTENT-TYPE' => 'Content-Type'];
}
