removeBits

    fn removeBits(self: *ReverseBitReader, num: u4) u8 {
        if (num == 8) {
            self.count = 0;
            return self.bits;
        }

        const keep = self.count - num;
        const bits = self.bits >> @intCast(keep);
        self.bits &= low_bit_mask[keep];

        self.count = keep;
        return bits;
    }