How to cogroup/join pair RDDs with different key types?

[Roger Hoover]

Hi,

I'm trying to figure out how to join two RDDs with different key types and
appreciate any suggestions.

Say I have two RDDS:
    ipToUrl of type (IP, String)
    ipRangeToZip of type (IPRange, String)

How can I join/cogroup these two RDDs together to produce a new RDD of type
(IP, (String, String)) where IP is the key and the values are the urls and
zipcodes?

Say I have a method on the IPRange class called matches(ip: IP), I want the
joined records to match when ipRange.matches(ip).

Thanks,

Roger