def _prefix_from_ip_int(self, ip_int, mask=32):
        while mask:
            if ip_int & 1 == 1:
                break
            ip_int >>= 1
            mask -= 1

        return mask
Return prefix length from the decimal netmask.
dataset/ETHPy150Open anandology/pyjamas/pyjs/src/pyjs/lib/ipaddr.py/_BaseNet._prefix_from_ip_int