check_once_cc_context_new_ccache_iterator
check_once_cc_context_new_ccache_iterator(context, &iterator, ccNoError, "when there are no existing ccaches");
check_once_cc_context_new_ccache_iterator(context, &iterator, ccNoError, "when at least one ccache already exists");
check_once_cc_context_new_ccache_iterator(context, NULL, ccErrBadParam, "NULL param"); // NULL iterator
cc_int32 check_once_cc_context_new_ccache_iterator(cc_context_t context, cc_ccache_iterator_t *iterator, cc_int32 expected_err, const char *description);