ParagonIE_Sodium_Core32_Int32::mask

    public function mask($m = 0)
    {
        /** @var int $hi */
        $hi = ($m >> 16) & 0xffff;
        /** @var int $lo */
        $lo = ($m & 0xffff);
        return new ParagonIE_Sodium_Core32_Int32(
            array(
                (int) ($this->limbs[0] & $hi),
                (int) ($this->limbs[1] & $lo)
            ),
            $this->unsignedInt
        );
    }