Is there a way to clone a JavaRDD without persisting it

[Steve Lewis]

 In my problem I have a number of intermediate JavaRDDs and would like to
be able to look at their sizes without destroying the RDD for sibsequent
processing. persist will do this but these are big and perisist seems
expensive and I am unsure of which StorageLevel is needed, Is there a way
to clone a JavaRDD or does anyong have good ideas on how to do this?