Group by isn't working

[fadrian06]

In groupBy method, line 365 you're asking if order property is empty. But it should be groups property, right?

When I execute method groupBy

$sparrow = new Sparrow;
$sparrow->groupBy('id');
print_r($sparrow);

Should be

    [protected::groups] => GROUP BY id

But I get

    [protected::groups] => , id