# File lib/cidr.rb, line 2027
    def wildcard_mask(bit_flipped=false)
        ret_val = nil
        if (!bit_flipped)
            ret_val = NetAddr.ip_int_to_str(@wildcard_mask, @version)
        else
            ret_val = NetAddr.ip_int_to_str(~@wildcard_mask, @version)
        end

        return(ret_val)
    end