leafo/lessphp#523
leafo/lessphp#540
leafo/lessphp#564
leafo/lessphp#566
leafo/lessphp#578
leafo/lessphp#584
leafo/lessphp#590
leafo/lessphp#592
leafo/lessphp#601
leafo/lessphp#603
leafo/lessphp#604
leafo/lessphp#605
leafo/lessphp#607
leafo/lessphp#610
leafo/lessphp#616
leafo/lessphp#619

611 -> no test for it
