iOS 11 Ringtone for No Caller ID

Is there any way (even a brute-force workaround) to assign a unique ringtone to "No Caller ID"? **Manually assigning a ringtone to all contacts and setting the default ringtone to something different is not an acceptable solution to the problem**, because both unknown callers and *No Caller ID* callers will use the default ringtone. I would like a ringtone that's unique specifically for *No Caller ID*. Thanks!