MongoCursor::wrapTraversable PHP Method

    protected function wrapTraversable(\Traversable $traversable)
    {
        foreach ($traversable as $key => $value) {
            if (isset($value->_id) && ($value->_id instanceof \MongoDB\BSON\ObjectID || !is_object($value->_id))) {
                $key = (string) $value->_id;
            }
            (yield $key => $value);
        }
    }