private function resolveNamespace(RequestStack $requestStack = null)
    {
        if ($requestStack !== null && ($request = $requestStack->getMasterRequest())) {
            return $request->isSecure() ? 'https-' : '';
        }

        return !empty($_SERVER['HTTPS']) && 'off' !== strtolower($_SERVER['HTTPS']) ? 'https-' : '';
    }
private function resolveNamespace(RequestStack $requestStack = null)
    {
        if ($requestStack !== null && ($request = $requestStack->getMasterRequest())) {
            return $request->isSecure() ? 'https-' : '';
        }

        return !empty($_SERVER['HTTPS']) && 'off' !== strtolower($_SERVER['HTTPS']) ? 'https-' : '';
    }
private function resolveNamespace ( RequestStack $ requestStack = null ) { if ( $ requestStack !== null && ( $ request = $ requestStack -> getMasterRequest ( ) ) ) { return $ request -> isSecure ( ) ? 'https-' : '' ; } return ! empty ( $ _SERVER [ 'HTTPS' ] ) && 'off' !== strtolower ( $ _SERVER [ 'HTTPS' ] ) ? 'https-' : '' ; }
Resolves token namespace.

@param RequestStack $requestStack
@return string
Resolves token namespace .