Ouzo\Utilities\Functions::extractField PHP Method

    public static function extractField($name, $accessPrivate = false)
    {
        return function ($object) use($name, $accessPrivate) {
            return Objects::getValue($object, $name, null, $accessPrivate);
        };
    }

 public static function extractExpression($selector, $accessPrivate = false)
 {
     if (!is_string($selector)) {
         return $selector;
     } elseif (strpos($selector, '()') !== false || strpos($selector, '->') !== false) {
         return Functions::extractFieldRecursively($selector, $accessPrivate);
     } else {
         return Functions::extractField($selector, $accessPrivate);
     }
 }