Improve snak testToArrayRoundtrip test.

The ->equals() method basically justchecks
to see thet the classtype is correct and
the hashes are the same. Having these checks
in the test allows failure output to be more
usefull

This will naturally not pass unitl the issue is
fixed in Change: Ic66442813528bb30

Change-Id: Idaa7bc41f1aee70b8e2897fdda4de73ea353a520