DeepClone - 2 Questions

I am trying to set up DeepClone and have 2 questions:

1. In membersToSkip and membersToKeep, how to I format these string arguments?  I have a number of members for each of these arguments, should they be comma separated?  space separated?  Formatted some other way?  ***Edit*** I found this post that indicates members should be separated by commas: https://forum.mendixcloud.com/link/questions/5322
2. How do I set up DeepClone so that it doesn't try to clone System.changedBy?  I have tried a few different ways, and still get an error message that says, "Write access denied for member 'System.changedBy' of object 'ModuleName.ObjectName'

Thanks for any pointers!

***Edit 2 *** Thanks for chiming in Rob.  What I found I had to do was put System.changedBy and System.owner into the membersToSkip list.  This may be because my source and target objects had different owners (and were last changed by different users).  I am not sure if the Java action expects the objects to be owned and last changed by the same user.