Ouzo\Utilities\Functions::startsWith PHP Method

    public static function startsWith($prefix)
    {
        return function ($string) use($prefix) {
            return Strings::startsWith($string, $prefix);
        };
    }

 public function getRequestHeaders()
 {
     $headers = Arrays::filterByKeys($_SERVER, Functions::startsWith('HTTP_'));
     return Arrays::mapKeys($headers, function ($key) {
         return str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($key, 5)))));
     });
 }