def setUp(self, testcase):
        # Keep a set of table uris on the test case that we have
        # decided to make into layered tables.  We make the decision
        # when Session.create is called, but in other APIs, we don't have
        # the same information available. This set would probably be more
        # logical to put on the connection, but when we reopen a connection,
        # we won't get the same Python object, so we would lose the set.
        #
        # We also allow a set of uris that we never want to be layered.
        # Tests can add to this list.
        #
        # TODO: When there are multiple connections on multiple home directories,
        # this may break down.  If we want a more precise accounting, we can associate the
        # uris with the home directory used.
        testcase.layered_uris = set()
        testcase.non_layered_uris = set()