public function getBottomRightOnBit() : ?array
    {
        $bitsOffset = count($this->bits) - 1;

        while ($bitsOffset >= 0 && 0 === $this->bits[$bitsOffset]) {
            --$bitsOffset;
        }

        if ($bitsOffset < 0) {
            return null;
        }

        $x = intdiv($bitsOffset, $this->rowSize);
        $y = ($bitsOffset % $this->rowSize) << 5;

        $bits = $this->bits[$bitsOffset];
        $bit  = 0;

        while (0 === BitUtils::unsignedRightShift($bits, $bit)) {
            --$bit;
        }

        $x += $bit;

        return [$x, $y];
    }